Throwing out a few suggestions, in the interest of keeping the league rules simple and bringing a bit more parity to the results. I know there are no perfect rules, someone will find a way to bend any league rule created, but here goes.
1/ Eliminate the SC bonus. + 20 is too large of a bonus. It creates an artificial 3 year cycle of finishing at the bottom. It seems that only the teams playing for the SC bonus can achieve it, not the struggling teams it was originally intended to help out.
2/ Change the out of playoff bonus so that all teams out of the playoffs receive the same bonus. If the SC bonus is eliminated +10 across the board to the first pick for all non-playoff teams would be easiest to calculate. Should remove some of the incentive in going for the #24 position. Gives a decent boost to 8 teams that could use this extra bonus, and equals the improvements that playoff teams accrue during the playoffs.
3/ Add in a minimum point total to receive the bonus. Perhaps 40 point minimum. How you get to 40 points does not matter, what you do after 40 points does not matter. But at least all teams will need to put up a few wins. If you don’t make the 40 point floor there is no punishment, you just don’t get the bonus that might otherwise come to you.
Overall the rules are pretty good, and many of the rules already created are doing a good job in what they were intended for, such as the 20 game minimum to be eligible for the playoffs. These are just a few tweaks to try and get even more out of this league.