I'm really confused about how spell scrolls work in this game. Can Wizards learn spells from them to keep permanently? And how do you use them in combat?

Yeah, you can do both and even write your known spells into extra scrolls as well.
Unfortunately I don't remember the exact command to do so... it was somewhere in the left side of the selection wheel... scribe scroll?

You need to have the scrolls and potions identified before using them, use "read magic" cantrip for that (do make a quick-key for that to save time). Using available scrolls is somewhere to the top right hand side in the selection wheel.

Okay I've figured it out, thanks.