I don't understand why the game insists so much that you go to Redcliffe first.

It's more than just Alistair. When you speak to Ser Donnall he tells you about the urn and tells you that Eamon is sick and Ser Bryant talks about it a bit as well. Those read to me like suggestions that Redcliffe should be your next stop after Lothering. Of course Ser Bryant also talks about trouble coming from the Circle, but it does seem as if you're being nudged towards going to Redcliffe next.

"One".

Do you know how to count? Or perhaps you didn't read the OP, since seems to be a common habit.

Right, that's exactly what my friend and I were talking about since she's relatively new to the series.She went to Redcliffe first because she thought that's where she was supposed to go based on what was said in Lothering and ran into a bit of difficulty once she got to Redcliffe and asked me for advice. She asked why there were so many suggestions about going there first because she was a little in over her head.

I had the impression instead that you had the habit to start topics that makes little if no  sense at all between this one and the other  you had started in the past.
The game doesn't imply to go to Redclieffe first,just because Alistair says something it doesn't mean that the whole game is telling you to go in Redclieffe first, just as Ser Donall that you've mentioned (which by the way it talks you about the Circle as well).Once again it seems to me people are reading what they want to read and claim to have found a sort of bias in the game even tough none of what they are saying correspond to the game implying anything.

The developers haven't offered valid reasons to abandon Redcliffe either way.
Even if you are gonna pick Redcliffe early on in the game, abandoning it doesn't seem a bright choice,because the game states that it takes one single day to save it,and one single day isn't enough time to deem it as a waste of time that wasn't dedicated to other quests.

Redclieffe shouldn't be available that early in the game.
If this plot was planned by Loghain as the game imply then Jowan should still be talking with Loghain while the Warden is in Lothering.
Clearly the devs forgot to lock Redclieffe from the map like they did for the Alienage.

Not impossible, but I agree difficult due to the two gating encounters (assuming not skipping them somehow).  They are indeed trying to discourage you from that path.  I could never really decide if that was a good or bad thing.

For a solo it is quite helpful if you can get inside the door since purchasing Lifegiver makes melee solo a whole lot more manageable, or even if you are still too poor, picking up Key To The City is still really useful.  There is some other stuff you can buy that is ok to get, but not as big a priority early as health regen cutting poultice use lets you start accumulating wealth a bit easier. 

Precious Metals in theory is there, but if you haven't done the Tower it doesn't matter, and probably will be too poor for the buy in, and it is really best to do if you have decent coercion and pickpocketing before starting.

Some of this is moot if you have Reaper's and allow yourself to sell it, but I didn't have that DLC when I did most of my runs, and then afterwards I would destroy it along with other DLC stuff early.

Heh, the easiest way to deal with the mercs solo, early, is just to walk past them on the left.  Don't even need stealth, which is amusing.

Loghain's emissaries or whatever you want to call them at the door were pretty annoying though.  Somewhat expensive or extremely tedious to kill with my melee characters.  Of course it is possible to intimidate them (I was always prioritizing other things, so didn't ever have the coercion to do it that early).

I'm trying to remember back to when I first played. I didn't go to Redcliffe, my first Warden was Dalish so my priority was to seek them out, but in the end I think I decided to go to the circle first then I went to the forest. I do see how it could be interpreted that Redcliffe is a priority and if you're a first time player you might think that the Arl will die if you don't follow up on that right away. Even when I've played not-so-nice Wardens I've always decided to defend the village because I like fighting and you get all that extra money from looting the militia soldiers. I'm also a person who likes to do side quests and I don't want to miss out on the notice board missions.

Not the Dalish themselves-but you do hear about werewolves in the Brecilian Forest. Guess where the elves are-The Brecilian Forest. There might be a problem there.

Just how early are you getting to Redcliffe and starting the Urn quests?  As many times as I've played, I'm always at least level 10 or 11 before I start them (I do a few side-quests in Denerim before I go find the brother - I mean, why not?).  Of course I always skip the little encounter with "Andraste" completely, so maybe I get off a bit easier.

I leave it for last, simply because it would be awkward to meet ghoul!Tamlen after Gauntlet!Tamlen says "We won't meet again".