I can tell you from experience that there's a very limited audience in OOTP world for a league where stuff changes all the time. Turns out, most OOTpers like boring consistency and the chance to dominant even if it's going to bore everyone else in the league.
Some of the weird stuff I did in my most recent league was creating international leagues that have massive talent and then doing a mid-season draft where teams can draft those players on cheap contracts.
Randomly spiking the size of the draft pool at random times.
Increasing (or decreasing) the talent pool available in the draft
Removing the salary cap like the NFL did for that one season.