First i need to say, i have tested the falowing games im my pc : FarCray2, Call of Duty Modern Warfare 2, Assassins Creed, Batman Arkham Asylum and others, all of then have worked very well runing with better graphics and faster than Divinity 2. But i will not complain about the graphics, that's not the purpouse of playing games, i can't sit in front my monitor to "watch", i "play".
I agree with you, the game don't have good graphics. But you need to be happy. Because you can play the game. I can't play it, it crash in the loading screen problem.
A lot of games don't come with an option to enable or disable vsnyc. This is the very reason my Nvidia control panel has an option to force it into the game, maybe your ATI control panel has the same option? That option works for me.
About your resolution problem, there is a post in the forun about how to adjust it.
About your antiasliasing problem... I don't see any antiasliasing here too... Maybe that game don't support it. Most games released today uses Unreal3 engine that guess what? Don't support antiasliasing. I have played Batman Arkham Asylum that uses that engine because of that i know you can't use antiasliasing on that games, i don't know what make Divinity 2 incompatible with it, but it's not the cause of the bad graphics in-game. Maybe the textures are not realistic enough?