As in letting the actions characters take is what powers the characters instead of traditional leveling?

I would be down with it. Only if...

-Don't let stupid things like damaging yourself on purpose count towards stat building
-You have to actually get a decent fight to up some stats
-Tone down prices for stuff (having your inn price be based off of your party's HP was LAME too)
-In order to prevent grinding make the game better balanced, but there should be optional areas to progress characters for those who want an edge vs those who want a challenge
-Simply casting magic doesn't increase the skill, but subtle ways on how you use it (ex: single target more than multi target)

That's all I got for now. I am sure some of you can think of better stuff!