Rapid Metamagic allows dragons to use Quicken Spell.

Multiattack and Improved Multiattack can make a big difference to those old enough to get all six attacks.

If you're allowing the most powerful dragons to have epic feats (Draconomicon says that Old or older dragons can take them) Ignore Material Components allows you to get around the "no expensive material components" thing.

Personally I think giving epic feats automatically at Old age is a bit much, I only give them to CR21+ dragons, but as far as I know Draconomicon is the most recent official version.