Was thinking about this.
I think a better way for this is to not change the basic stat for melee damage, leave it str.
Have the ability to have other stats effect combat, but not replace str.
Have instead other stats give other bonus', like fort bypass, MP, doublestrike, increased crit damage, etc.
Like have a feat or enhancement give another stat 1/3 of modifier to MP.
Could be for defensive also, like the Armor Class Bonus (monk) or Divine Grace (paladin).
Spreading out things for stats, would decrease some min/maxing, and make some more gear options.
Balancing can be by which tree they are in, and by damage type of buff type, ie insight and others.
Would be nice to also see things based on some skills. Like replace the useless Timeless Body (monk level 17) with a cool thing based on balance.
This could make some skills more useful.
This would effect many builds, and give more options and styles of play.
Like a fighter that takes an enhancement that makes his Int give a bonus to combat feats, or wis to crit damage modifier.
This gives uses to "throwaway" stats, and more choices in play style.