The only problem with going down that route is that you are effectively consigning the vast majority of spells to the bin because they can't scale up into epics and the problem is only going to get worse as we move to a cap of 30 - generally mob hitpoints scale faster than spellpower does, so without increases in damage related to caster level all existing spells are going to suffer. I would prefer not to be in a situation where only a small handful of spells were relevant in epics, it kind of defeats the reason to have the scores of different damage spells that we currently do. And that applies not just to damage spells - many of the buffs are also getting less and less relevant - many items now come with blur or even a few with lesser displacement, spells like barkskin and shield of faith top out at +5 whereas items go to +10, resist only goes to 30 whereas items go to 50 - the list goes on.
Also I'd prefer that we not have to spend a feat to gain one spell - a feat to open up the option of epic spells would be preferable. If that's not possible I'd rather they just made any new spells level 9 ones and have no cap on the maximum caster level - doing it that way means theres no power creep at lower levels but theyr scale into epics. I'd also prefer that some of the existing spells that currently cap at level 20 be unlocked, or capped at level 25. It would also encourage people to use the magister destiny rather than shiradi as the magister one provides caster levels whereas shiradi doesn't