Spell Blocking

[Hornpipe2]

However, if I wanted to change that formula to make spell-blocking viable with any amount of resistances, I think I'd add in a blocking delay. e.g. you can only block a spell every X often (maybe the equivalent of 1-2 times per second?) - that way, being bombarded with spells alone could never put you into block-lock.

This is a good idea too. How well do you think it would work to be unable to block while attacking? That way you would never be interrupted in melee but you'd have your chance to block when you are vulnerable.