A few other prospect-player development adjustments we'd prefer not to explicitly detail
Something that will help tip the scales between a great player and a great prospect will be if these "adjustments" are also on the back end of a player's career. As it stands right now, we know a 33-34 y/o player and 37-38 y/o pitcher are in for a steep decline. So, for me, trading a 20 y/o prospect for a 34 y/o player is nothing more than a 1 season rental. There's virtually no reason I can think of that would make me want to trade 11 seasons of production for 1 season of similar production.
Which leads me to another suggestion. The fact that we have 10 seasons of guaranteed control(3 min, 2 arb, 5 LT) of a player is troublesome. I'd really like to see some players refuse to sign LT after 1st or 2nd arb. And some players refuse 5 year long term deals before going to FA. And, along the same vein, some players in the last year of their deals, who will re-sign at the beginning of the season, either raise their demands as the season progresses or refuse to sign at certain points in the season.