i use a cap that's above what the largest market can afford - by a small amount ~10M, which is also my max cash on hand limit.
i could be wrong, but i think a hard cap causes teams to spend a max % of the hard cap on 1 player. it seemed to keep salaries a bit lower than they would normally be.. just the "extreme" few players at the top were different, the average was still similar. it could have been the setup too, i can't guarantee this effect.
i use a pretty similar setup each time. set markets and such on my own blah blah -- the max contracts were never higher than ~32m. i would normally see a bit higher as a max after a long enough period of time even reaching ~40m.
as far as evening things out, you can easily predict this stuff using baselines - even gate revenue to some extent.
you can make it 100% stock by zeroing things out or possibly 100% gate revenue sharing would work? or zero that out too. leave attendance baseline if oyu want ot see spectators
the national media contract can be set to the same per team - this value can make it 100% stock by zeroing out other revenue streams that vary due to various factors like success. or anywhere in between.. you can reduce it and still have some deviations from baseline for various teams.
if you do edit market sizes, i think they "move" toward a more normal distribution curve if you leave them to their own accord over time -- a long period of time if they are all 5's, 6's or something. i could also be wrong about htis, but i noticed a heck of alot more shifting when i didn't use a distinctly bell-curve distribution.
either way, they can change over time, and it could have just been luck too. if you make revenues stock, it won't matter either way.
*oh, if you change this stuff after leage creation, you may have some old local contracts giving money.. not sure if it updates it or not... so double check that.. maybe zero them out per team, if needed (team settings with commissioner mode on)