Your suggestion is good btw, but I think some of them are already have its effect in matches. They just don't show it to us obviously, like streaky shooter and talisman. This has its effect on most of the players, but greater on the star players in the team with high agressiveness ( which is also hidden).
Your view on adding
prima donna and
super sub is good in my opinion. I think this will give managers a better idea that which player will become franchise player and which player tends to play better at sub even he has the highest salary with HoF potential. This way, managers will know who to train best in their management plan.
I have a player
(50827696)when he plays sub, he's averaging 12.2pts per game in 17 minutes.
However, when he plays a starter(or 48 mins), his average only rises to 14.8 pts per game in 44 minutes. (based on self-calculation)
He performs better at bench than starting. He just didn't take up much more shots when he starts, which i don't know why, given that he has the second-highest salary in my team with the best offensive skills. He may be a super sub this way.
BTW I think 'hot and cold streaks' already has its impact in game for the team. Even for the player. Because the team will lose points when they have a player is in cold streaks, and forced to let other players to shoot who's shooting and scoring chance are
not as good as the cold streaked player. If the star player of your team is in streaks, I think this even has a bigger impact to the team as he takes up the most shots.