These need some tweaking.
1. They need to be based on the casting stat of the class, not just INT.
2. Rangers need to get benifit from heal.
3. The 1:1 ratio is too low. Give 3 spellpower for each point in the skill.
I don't know of anyone who takes any of these other than bards taking perform. This will place a burden on many characters (wizards and artis are probably okay.) Take my 3rd life cleric for example. With 36pts to work with he is max wisdom and charisma and the rest goes into Con. He has 8 INT. Concentration is a must have skill. Now so is heal... so now he needs two more points of intelligence. Was that considered?
Same goes for a sorc... max cha and max con. Not a lot of skill points to go around...
There are builds that don't need skill points, but to those builds that do, they are precious. Due to the difficulty of getting more skill points on things like clerics I think that each point invested should be worth more than 1 spell power.
Thanks for reading.