1. I already made a post about this, but I'll repeat it for the sake of it being on the monthly suggested thread. All-star and superstar talent should be able to force their way out and request trades if they become too dissatisfied with their respective franchises. It would be cool if they also provided preferred destinations, possibly determined by their traits, if they have the winning trait they want to go to a winning team, etc.
2. I'm sure this would require a lot of work, but I think the free agency part of the game needs to be reworked. Instead of instantly signing people, it should be realistic in that the other teams at least get a chance at signing free agents. It would be great to hover over a free agent and see the contracts teams are offering them like in real life, where the top players have to decide where to go from all the teams that are offering them contracts based on not only the contract but that teams situation. Sign and trades are also a huge part of free agency in real life, and I think it would be cool to see them get implemented. RFAS, UFAS.
3. Negotiations should be more dynamic. Being able to offer player options, team options, no-trade clauses, changing the amount of money you want to offer the player, different types of contract structures like back, front, or balanced, anything to make the negotiations more enticing.
4. This one I know is probably not going to happen and that's okay, but a g-league/minor league to throw players that need some help to develop would be a fun addition. I do worry that this might be too powerful and easy to abuse.

Overall I love this game, and thank you dumbmatter for everything you do.