I think I found a reliable way to find and modify values.
Consider this a BETA update and please report any troubles or in fact any feedback you have.
EDIT: Added Maximum Cast Rate script. Sadly doesn't effec cast delay spells like Meteor and Frozen Orb
EDIT: Added No Cast Delay scipt. Target for the delayed spells behaves a little weird. You can i.e. cast multiple Frosen Orbs at the same time but unles you move they will all be dirrected the same way until the first one explodes. Same is for Blizzard and Meteor.