While people are throwing out ideas, I just thought of one. How about all free agents under say 22 instead of becoming FAs get put into a separate draft once a season. It kind've incorporates the older/useful player thing without modifying the current draft. Probably needs further defining: over 70 TSP and some other modifiers. Not sure how you decide the order, if it's reverse order it may increase tanking. Unless you have to invest lots of money to this new draft, it'll also not take as much money out of the game as the current system. How you decide which FAs go into which leagues draft I'm not sure. Maybe these FAs could just be added to the current draft pool and you get an extra pick or two per season, I don't know.
So, on balance right now I don't actually like it, but there's possibly something there that someone smarter than me can work out?
In general: I enjoy these! Shame the offsite is a closed shop for USA managers, but I guess I understand why it is.