Perhaps Bard could be limited to 1 Power feat (or so) per Multiclass feat.
This way, a Bard would have to choose between Power versatility combos, and having a limited feat stack.
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Personally, I'm not sold on some of the problems at Epic levels.
I feel like the word "Retreat" is too Not acceptable.
Additionally, the limited use of Rituals, specifically Divinations, makes Epic that much harder.
I may be way off base, but my caveats here are : personally , and I feel.
Consider the Boons option box, in DMG2; kinda a low magic variant.
The Boons replace the 2 Mid magic item slots, and ditch the Hi and Lo slots.
In return the players don't get much, just the attack damage and defense bonuses.
What do you do with all that excess moolah?
Spend it on rituals.
Yer still gonna hafta "Retreat" with a capital R.