The $4 for last place should be abolished for two reasons:
1) It inadvertently rewards tankers.
2) It hurts recruiting. Previously, if an owner told me he wasn't re-upping, I'd ask if I could bring in a replacement before the roll, to let the new owner take care of pending FAs, 40-man roster moves, minor league promotions, etc. Usually, the departing owner said yes. Now, the departing owner has incentive to stay until the roll, to collect that $4.
3) It can delay the roll. Not being able to bring in replacements before the roll means more teams to fill during the roll. That's harder to market on the classified -- all things equal, an owner will want to go to a world with one opening vs. one with several -- and can delay the roll.