I agree with every single suggestion in Karbuncle's post except for Demi. That sounds a bit overpowered unless you make the accuracy rate horrible or tie it to Chainspell.
I'd also like to see RDM get MATK and MACC down spells. Also, give RDM a variant of Amnesia. Instead of locking job abilities it could have a random chance of blocking TP moves. The activation rate could be set fairly low to keep it balanced.