I want to do my first playthrough pretty blind, but I wanted to check first if there are any specific skills or combinations that should be avoided due to a lack of usefulness or that cripple my ability to progress through the game.

Anything I need to worry about?

As far as I know, there are no useless classes/skills. People prefer mages or two-handers, though, and tend to avoid archers and dual-wielders. Just bear in mind there's only one sword&board tank character who can join your party, and several different mages.

Most of the straightforward characters you think about will work out. Equipment wise, there is no one joining your group that will want to use heavy armor, so going that plus maybe a two-handed weapon will not have you throw away every heavy armor you find instantly.
As was said, there are already decent mages, especially for the damage dealer role that even if you try you will have a hard time competing with. Support mage could be a viable niche, though.