Empower skills

I would love to see a system implemented where you can sacrifice skills (temp lock them) so they become unusable, but at the same time getting a performance boost for all the remaining skills/spells with an effect stacking with the amount of skills you descide to sacrifice...

So if I descide to stop using 20 skills/spells... my remaining skills/spells should become 20% more effective and even get a faster TP/MP (HP?) regeneration. This way you can concentrate on what you want to do and become very good at it as you would require less TP & MP to maintain the same result... making your job easier to maintain... so even the worst of healers would never run out of MP again.