Just curious, will I be able to cast level 9 spells and have a nearly-invincible monk, or do I stop learning new abilities at level 10?

I'm playing through this game either way, it's the best d&d computer game I've seen! just want to either start looking forward to good times ahead or get the disappointment out of the way early :D

Your characters will continue to gain new abilities and you'll get access to higher level spells (not sure if any level 9 spells are implemented, but I do remember getting access to Horrid Wilting, a lvl 8 spell). Your higher level characters will be able to crush most of the default enemies towards the end of the game, but there are also some new fights that Co8 introduces that will provide a nice challenge for the higher-level characters you end up with.