Morrigan Confusion

Ancient Elves:

Yes, but Morrigan could have pursued Ancient Tevinter, The Avvar or any other old civilization. Furthermore, after the events of DAO, Morrigan only knowledge of what her mother is, is that she is not human.

Morrigan did not know what her mother truly was until the end of DAI.

Again...

Why Elves?

Why activate an ancient mirror?

Maybe will get lucky and DA4 will give some sort of answer(s).

"Because I taught you girl." Flemeth makes this point as to why Morrigan does many of the things she does. She taught her to value the old ways and to recover and protect lost knowledge. Since Flemeth would have taught Morrigan not to believe the Chantry's version of history and may even have hinted that at least some of the Dalish beliefs about the ancient elves were true, Morrigan would be encouraged to investigate further. Morrigan certainly understood a fair bit of ancient elven which I imagine can only be because Flemeth taught her. Her ideas about some of the elven gods seemed to chime more with what Solas knew about them than the Dalish ideals. However, for some reason, Flemeth kept back the bit of information about Fen'Harel being Mythal's ally. I suspect that Morrigan knew all along about the Well of Sorrows as well as the eluvian in the Arbor Wilds but just pretended it was fresh information to her, because I'm fairly certain that Flemeth wanted her to go there.

In the Dalish origin we find an eluvian and we come from Sabrae clan, whose Keeper Marethari had a close connection to Flemeth through the latter having done her a favour in the past. It is possible that Flemeth knew about the eluvian in the cave before Morrigan left with the Warden as at some point she had to have called in the favour with Marethari and that is why the clan ended up on Sundermount. If so, she may have mentioned an elven clan finding an eluvian to Morrigan and explained what they are. Alternatively, they could have been mentioned in her grimoire. Either way, that would have given Morrigan the requisite "nudge" to discover more.

We know at the end of Origins that Morrigan has been seen crossing the Frostbacks towards Orlais. Initially that may have been when she attempted approaching the Arbor Wilds but realised it would be too dangerous to try and find the eluvian there. It is not clear exactly when Morrigan first made contact with Celene but the latter had apparently always been interested in the occult and forbidden magic, so Morrigan would likely have heard the rumours and made an initial approach herself. At first Celene probably kept her at arm's length, particularly as Court Enchanter Vivienne was said not to approve, but as Gaspard became more of a problem, probably thought Morrigan could prove useful and sent for her. It is said that Morrigan would then return every few months in the dead of night with some new item to intrigue the Empress. Clearly Celene knew nothing about eluvians before the events of Masked Empire in 9:39/9:40 but it was not long after then that Morrigan was officially introduced at Court. Whose idea it was to dredge the eluvian from the lake is anyone's guess but I would think that Morrigan was effectively manipulating Celene into thinking it was her idea to do something that Morrigan wanted. I don't know why she wanted that particular eluvian since there was already one at the Winter Palace but perhaps Morrigan thought the dredged up one could be made to operate independently of the network that Briala controlled, as proved to be the case, except Morrigan probably never admitted to Celene that she had successfully activated it.

But why would she go to Tevinter, when he has a way straight to the roots through the Eluvian?

No offence taken but you asked questions and I tried to answer them from what I knew and what can be gleaned from the various official sources. However, as Phoray points out, even if what we assume is true that doesn't mean that the writers may not decide to change things further down the line.

For example, in the Dalish Origin, Duncan knows about eluvians and says that they are associated with Tevinter, although the hint was always there that the reason it was part of the elven origin was because of links to them. It was found in an underground complex that seemed to combine both Tevinter and elven architecture. There was at least one statue to an elven god there. A comment can be made that it looks like humans and elves were living in the same place and worshipping an elven god.

Now all this can later be revealed by further discoveries, say up in Tevinter, to explain what was going on here, or it could have simply been a possible idea for past events that was later dropped. We can speculate as much as we like, that is half the fun, but nothing is proven until the lore is revealed.

At least with Morrigan we have a plausible reason why she took such an interest in elven lore now we know who Flemeth is/was. As Imshael says in Masked Empire, you always have to respect old elven magic, which was clearly far in advance of anything Tevinter achieved. However, I always wondered why, if elven magic was so advanced, Tevinter was able to conquer them. The answer turned out to be that they didn't. What Tevinter conquered was merely a remnant of their civilisation and according to Solas the majority of their magic was long gone through the raising of the Veil. If Flemeth even hinted this might have been the case, naturally Morrigan would want to go to the source for her information than the "scavengers" of what remained.

Why Morrigan acts as she does is far less problematic to me than the sudden discovery of a whole new race of beings, the Titans, in the Descent and Trespasser and being asked to believe that no one was aware of their existence until the Inquisitor just happened on the information. Or why the Dalish have remembered some of their history so accurately and yet totally forgotten other important facts, including the existence of the Titans, when the two sets of information seem so closely linked in the DLC.

So I am waiting for them to explain the widespread racial amnesia that seems to have occurred among humans, dwarves, elves and, we shall no doubt discover, Qunari too.

True.

Or how about the fact, suddenly the Dalish cannot have too many mages in their clans, yet previous knowledge indicates they welcome such talents.

Dunno about the Dalish remembering their history accurately, I mean the player can play an elf and when Morrigan speaks to him/her about Mithal, they are completely dumbstruck.

This is my favourite gripe. The Dalish teach that all their ancestors were once mages. The aim of recovering their culture is so that they remember what it is to be "true" elves. There is even a suggestion that their gods deemed them unworthy of their immortality because they "forgot" and that in contradiction of the idea that the gods were imprisoned and cannot escape, in fact they will return when the Dalish remember what it is to be a true elf. Their leaders are mages because they are deemed closer to what a true elf should be. All this suggests that every mage would be celebrated as getting them one step closer to recovering their ancient glory.

Then along comes DAI and apparently mages are so feared, and Keepers are so incapable of training more than 2 at a time, that every 4th mage is dumped in the woods or told to get lost. Suddenly the very reason they keep on the move, to avoid the attention of Templars who would either kill or take their mages from them, is rendered valueless because they cull the mages for themselves. It is laughable.

Well actually the reason given was not to avoid the attention of Templars but because of the risk of mage possession, which is exactly the same no matter whether you have one or several. Also Merrill stated in DA2 that mages were on the decline in the Dalish, so every mage would be precious. Tell the adult mage to seek out another clan but according to "Dalish" in DAI the Keeper simply told her to get out and see the world (that always sounded suspect to me). Minaevre was only a little child. The other mages in the clan had to be older than her, so ask them to stay on the fringes and disappear if any Templars come their way (which was actually more likely the reason they left her in the woods, probably intending to come back later after the Templars had gone).

Still if this was a general rule among the Dalish and clan Lavellan were the exception, as you can claim, in not doing this (along with Sabrae clan and Zathrian's clan) then it was a retcon from DAO as the on-line Core Rule Book confirms. There it quite clearly states that within the clan there will a Keeper and their First and all other mages are considered apprentices. It also confirms that the Templars hound the Dalish no matter how many mages they think they may have. Even having just one mage, the Keeper, is considered one mage too much.  Actually if your scouts spot Templars approaching, surely you just make out there are no mages or, as I say above, get them to disappear into the woods until the Templars have gone.   How are they going to tell?

Don't ask me why the Templars left Sabrae clan alone for so long, unless you send Feynriel to them. Considering Kirkwall was meant to be the HQ for Templars in the region, they were surprisingly inept at policing the mages even in their own city. It was really laughable there that all the really dangerous mages were running around on the outside of the Gallows. You can actually walk into the Gallows and tell Cullen to arrest Anders with him actually standing alongside you and he still walks away from the place. Meanwhile Hawke can actually be a blood mage apostate. There were some aspects to the way the plot was managed that really didn't make sense in DA2.

Just one question: how the Templars know, how many mages exactly in a clan?
The three-mage-rule is very inconsistent with everything that we knew about the elves. 

One-kind three-mage-rule I can imagine: if a clan have more than three mages (1 Keeper, 1 First +1), they able to send one to a clan, that doesn't have three mages. Never forget: the mages are rare (according to Vivienne speaks about the war: 1:100)... even if among the elves the ratio is higher, the mage children are important – a treasure, not a curse.

This was the original "3 mage rule", as outlined by Merrill in DA2 to explain why she had been given to Sabrae clan, because at that time all they had was Marethari. If she had died without a First, the clan would have been without a Keeper. Which is why they were permitted to adopt Merrill as her clan seemed fortunate in having more than 3 mages. Whilst it would have been hard on Merrill having to leave her birth clan, this at least made sense and her own clan would have assumed she would be treasured by her new one.