Okay so i play a mage. I just beat the College of Winterhold questline. What do i do now? Are there more factions/guilds for mages in skyrim?

Well, not that I'm aware (I can't say nothing about the DLCs because I'm on the PS3 T_T ). What you can do is join the Dark Brotherhood and the Thieves Guild if you like Illusion Magic. None of those are perfect for casters, but you can give it a try... Other than that, I would say you can hunt for Daedric Artifacts, which is alway fun =P. Main Quest and Civil War are other options. But if you really want a Mages Guild, like the College, I don't think you will find it.

No. Theres not much for us evil wizards.

The azura's star mission is pretty cool... one of my favourites infact. Thats magic related.