Stars are only simbolic, they show how player good is for your lvl.
Constant promotion is problem, endless number of levels.

What about this system, making some sort of play-off that consists of most sucessful teams.
So it roughly goes like this; X number of promotions->same lvl play-off in elite league->promotion
For example
After 3 promotions, 3 best placed teams from same lvl and server enter elite league. Other teams cant get promotion unless they enter and won (or archieve high finish) in elite league.
Elite league should be on same level, not higher lvl, so managers shouldn't have to buy new players. They should be able to buy same quallity players as they had in previous season.
So they actually aren't promoted, but they enter competition to earn promotion.
To prevent tanking, 3 worst placed teams should be relegated, and their managers possibly sacked (based on other results from cup and cl). Also after relegation team would get worse financial contracts as a punishmet....

This is only basic idea without details.