Jowan: Hero is a Good Look on You

That depends on how you feel about circles or how you roleplay as

Personally I don't like playing as mages but suit yourself

Amell/Surana is Irving's apprentice and star-pupil.

Even if they've been best friends for years, Jowan could not risk telling them all the details of their plan to escape the Circle, because of the possibility they might have decided to go and tell Irving. Same reason why Jowan kept his relationship with Lily secret from his friend, because he didn't want it anyone to find out and risk getting her in trouble.

As for Jowan not telling us about being a Blood Mage, who would admit to that?

Even after he does use it against the Templars, he claims that he only dabbled in the hope it would make him a better mage. This fits with his earlier comment that the Circle has been known to make Tranquil certain apprentices they feel "aren't strong enough" in their magic. He even believes this was one of the reasons he hasn't been called for his Harrowing yet, despite having been at the Circle far longer than Amell/Surana.

It does seem that secrecy tends to become a trait of anyone who's lived in the Circle, likely as a result of rarely getting any privacy whatsoever from either their Mage colleagues or the Templars constantly watching them.

We even saw a conman exploit this trait to sell the "sole copy" of the Deus Vi Eternus  to several Senior Enchanters, banking on their predilection for secrecy to keep his fraud hidden, because none of them would want to share any potential discoveries with anyone else.

Jowan was afraid he'd be Tranquil. This is fear, not knowledge. Can be irrational. I can imagine, that asking a friend to help escape with his love, would much easier, than speak about the blood magic. Jowan probably wouldn't able to organize the escape alone, so, they need some help. And the escape was only Jowan and Lily's secret, the blood magic is NOT his secret. AND: Lily is a Chantry sister, hate the blood magic, and fear from it. Likely, Jowan learned this before Lily, and doesn't want to use, just live freely. So: Jowan have NOT only one reason to NOT speaking about blood magic, but still asking for help in their escape 

Anders and Jowan was able to finish their Harrowing (Jowan didn't believe, but he was able to it), and was not even a coward. He afraid from the Harrowing, but offered his help for Connor. He was a blood mage, probably he didn't totally against the blood magic, this is not so unbelievable: in every Circles were blood mages.
Anders was different, but you're right, he has basically the same purpose: live freely and in peace. He considers blood magic as evil thing, and probably blames blood mages for the reasons of Prison Circles. Anders was a spirit healer, this also requires high concentrations. He spent a year in solitary confinement (after his last escape before Vigil Keep), but he did not turn to blood magic. Anders was not a weak mage. No one of them was weak mage, but both of them have a big weakness: they wanted to live as everyone else.

If the Circles do not exist, they would have been normal people. None of them wants power over the other people.

Jowan's intent was his freedom, Loghain's intent was to poison Eamon. As I said: Jowan's weakness was his desire of freedom, and his fear from tranquility. He was able to Harrowing, he was able to save Connor. This was his Harrowing, if the Warden let him do it. He asks for the redemption, he wants to save Connor. He's not coward. 
Awakening Anders a sad, angry man. He's not so much differs from DA2 Anders. His opinion has not changed. When Justice said, that he would be able to make something for their fellows, he never was able to stop to think about it. This was Awakening Anders, without Justice. HE wanted this revolution, not only Justice, Justice only strengthened him. The only difference is Justice's presence inside him, ofc, his behave changed a bit: he more judgmental, determined, and no longer used his charm to survive. He did not need it. Finally, he could have allowed himself to be an asshole like he just wanted to be. I think this could be a relief... Justice corrupted, (Anders blames himself for it, but this isn't right, at least not totally right. Justice's corruption already started, when he left the Fade. The spirits don't understand the people, the "real world" is difficult to them. The Justice's not so clear anymore, and the people's emotions are hard, and Justice isn't the Spirit of Compassion. The spirits don't have emotions as people, don't even know the emotions of people, only can mirrored them, and probably can learn. Justice learned friendship, mercy and anger, from Kristoff's memory, Anders and Warden's companions. This knowledge mean his "corruption".  But didn't turn into a demon. Justice and vengeance's borders may blur. You do not know where the justice ends and where the vengeance begins.
Jowan and Anders both have a weakness (strong desire for freedom), but none of them is a weak mage. This both could have safely with their talents without prison-Circles.

Your examples are very good, these are strong people, all, someone better and stronger people than Anders, and definitely stronger as Jowan, and older, and have a different background. Every people's different.
Irving is an old man. Probably broken, but still strong. Have a purpose in the Circle. A servant, but benevolent, at least mostly.
Bethany had the purpose of being prisoner of the Circle, this makes her strong, and she never was a slave before. Much more easy to break a child, than an adult person, who choose his/her destiny.
Morrigan never was a slave, but you can imagine her in the Circle? She would be never Wynne, who accepted her fate (and Wynne has never a safe home, his childhood was a nightmare). True, Morrigan never would be able to start a rebellion. She doesn't interest people, who don't want to free themselves. She says those people does not deserve freedom.
Vivienne just a power hungry hypocrite, who use people. She is really dangerous. I think, if she becomes Divine, she kills much more people (rebels), than Anders, but I know, who have an army, is not a murderer.
Dorian wasn't a slave of the Circle, we don't know, how he would behave if the Templars kidnapping him in his childhood. He's not live in Southern-Thedas. He's a very bad example in this case. But, he would be a good example for me. He's a live example, that the Mages can live freely, if no one wants to explain to them that their talent is a curse. He hates blood magic, because his father wants to use on him, and he saw, what easy to solve everything with blood magic.

I didn't read Asunder.

Jowan is not the sharpest knife in the drawer, but still able to control his magic. His phylactery may be destroyed, but his fear from Templars is not. Loghain used his fear. Fear of persecution is difficult to overcome. And do not forget, he escaped, he was a wanted apostate, even if his phylactery was destroyed.

In fact, if Fenris join to Meredith first, later Hawke can convince him with "I assumed, that the freedom for slavery means something to you" – or something similar. So: Fenris capable of recognizing, that the Mages are slaves.

How could the city guards find any criminals exactly? They don't have phylacteries. The phylactery is a blood magic based leash, makes it very easy the Templars' work. But the lack of it does not make it impossible the pursuit. The Templars were able to catch most of the Starkhaven apostates.

Slavery, when your life depends on people who can kill you without any consequences, and you don't have a chance to go away. Cassandra can't prevent this completely, but she's not bad. At least she's not corrupt and malevolent. Better than before, but not ideal. The point is that it never will be the same as before.

The golden cage is just a cage, no more. Someone can live in cage, but it does not mean that this is healthy. People can be mad, if they closed for indefinite time / their lifetime. The Circles are very good things, as schools, libraries, magical research centers, but dangerous as prisons. The phylacteries are useful things against the rogue mages, but if the Circles are prisons, better if the Mages try to destroy the phylacteries. If the Mages is prisoners, they natural enemies with the Templars/Seekers. If the Mages are free, they are allies with the Templars and Seekers against the criminals. And this absolutely fits Anders' plan as well.

Some slaves have a good master, who give them good food, bed, and safe life. Some slaves don't want to rebel, because never knew a different kind of life and have no home. So: the slavery is acceptable. Orana, for example, can justify, that the slavery is a very good thing for the slaves.

And again: The Mages aren't walking bombs. And don't want to destroy the world, because of they not even idiots. The world is their habitat.
Why Tevinter still live? There are many blood mage, and still a strong state? How? Tevinter should have been destroyed accidentally by the lame Mages, for a long time ago.

The Mages depend on the Chantry, and the Templars, the Chantry's army. The Templars can do everything against the Mages in the Circle, what they want, without any consequences. The Mages can't have a family or some privacy. The Chantry can take away the Mage children from their parents without their consent. The Mages are property.

Tevinter is strong enough. At least not a black hole on Thedas' map, as should be, if the abominations would be been so common. Accidents always happen, as I said.

Full control over their fate? They can buy a house at a lake, and live with their family, without being watched by anyone constantly? They don't need "guide". Education needs. Anti-magic law enforcement forces are needed (mages, seekers, templars), and registration (phylactery). This would more than enough. It would be a safer more humane system, than the Circles.

One-two Templars to sleep in every Mage family for guarding them and accompany them everywhere? That sounds very fun.
What is "full freedom"? Everyone should take responsibility for themselves, and may not endanger any others' freedom. And if the laws are not inhumane, they should obey them. This is simple.