You said:

"The biggest problem is not so much the lack of a level playing field, but the lack of trading partners in leagues with many unmanaged teams. It's pretty hard to rebuild a team when a substantial number of better players are locked up on unmanaged teams."

If you have a bad team, why would anyone trade you their better players? Are you looking for trading partners or dumb trading partners?

If you want to trade your high draft picks and young potential for stars, is that the way to build for the future? If you take the good players from the unmanaged teams, does that improve the balance of the league?

This logic escapes me, yet you aren't the first to mention it.

I do agree that trading helps the league and unmanaged teams or inactive managers take away some of the fun. I don't think trading improves league balance, often it does just the opposite.

The draft can improve balance and I for one would like to see the FA draft move to the non-serpentine type like the rookie draft. Perhaps do one draft on record and the other on PB value but help the weaker teams a little bit more.