It definitely seems to me that no further advancement in BA, hit points, skill points and saves seems a bit harsh. OTOH, do high level spellcasters really need more spells/day?
Seems logical to me that high level wizards might want to spend more of their time on research and teaching; post-graduate work, if you will. OTOH, they might start up a magic-item making factory in order to fund their new research hobby. Or maybe there's some sorta Ring of Power type relic they are looking for, or mystery they are trying to unravel, or hideous monster to kill.
Often IMC PCs tend to advance pretty quick in game time, and I understand this is not too uncommon, so I can imagine that high lvl characters still at a young age presents a conundrum--in your mid-20s as a human, what are you going to go with the rest of your life? Imagine the dilemma for an elf.
OTOH, I suppose they can start a new class.
Anyhow, thanks for the suggestions for other templates--I'll take a look at these.