I like the idea too!
Nba rules - is it 10 techs in a season and you miss one game? Not sure. maybe something like that. If you get 3 flagrant fouls in a season, you miss one game.
My only concern with this suggestion is as follows -
The hidden aggression stat is exactly that....hidden. it can be identified by analysing the players stats, number of fouls per 48 mins etc.
But if BB implemented this 'punishment' for flagrant fouls, then this hidden aggression factor I feel, would need to become less transparent. It could just be something as simple as keeping track of how many times the player gets suspended, inside the player history column. Or number of flagrant fouls in the year.
eg: If im buying a player on the transfer market, and say the limit is 3 flagrant fouls in the season, and say its coming close to finals time, I wouldnt really want to buy a player who has already had 2 flagrant fouls for that season. Or that player would be worth less on transfer market.... OR at least if I bought him, id have that information to know what risks I am taking.
Dont get me wrong, I love the idea and im sure it would be easy to implement, just thinking outside the square for other impacts. Implemented correctly with some kind of tracking or information about the number of suspensions, or flagrant fouls (or however its implemented) definately a good suggestion.