I've been around the game for a little while, but I have yet to ever tinker with the 'Foul Trouble' trigger (Options are More aggressive, Normal, and Less Aggressive). Does anybody know if, and to what extent, this feature works?

I would assume it would be strictly offensive, seeing as it is in the player distro section. I think it would be interesting if it would allow me to keep a key perimeter defender on my squad to play "more aggressive" defense, while the rest of my team plays to prevent the interior.

this setting affects how your players are substituted when they pick up fouls. More aggressive means they will stay in the game longer after picking up say an early 2nd foul. Less aggressive means they will be yanked quicker.