regarding the rule not allowing to buy a player your team sold (years ago) before.
i would suggest to delete this rule or to assign a time limitation to this rule. e.g. after 2 years it’s aloud to buy him back.
or if you sold/released a player as a youth (not finally reached his improvement limits), you’re able to buy him back someday.

The time limitation sounds reasonable. I’ll add that to our list of improvements.

Thanks!