Shitty wizard is a trope in any Dragon Age game. You always have one mage with their own agenda, which can end not so well for you, but Solas takes the cake here. I wasn't surprised though, he was a racist, mysogenic guy right from the start, so his plan does kind of make sense from his warped perspective. And he cuts off your arm to save your life, there was no other way. I don't like this character, but I felt it right to mention, that he did some things to actually help (after having caused most of the problems though).
I think, it's entirely possible, that Gale turns out to be a shitty wizard as well. It could be tied to a story event and how you decide, if he might betray you or not. Or he might find Mystras favor again and gets power-hungry. Tbh, I wouldn't mind, if they'd go down that route, it would be an interesting development for Gale.
