Here are a couple of suggested improvements (not in order of priority & excuse those already suggested by other users):

1.  should be able to pick a particular match up to exploit (eg.  if your opponent puts Peja anywhere on the floor, you should be able to tell your team on offense that whoever Peja is guarding should get the ball and shoot, since Peja can't guard anyone), this will make people pay a price for putting all those 3point shooters who cant play defense (Peja, Nash, etc.) on the floor;

2.  should be able to designate a player to feed (if desired) or rely on your usage percentage;  perhaps if you feed a player too much over their normal usage % the player get fatigued quicker over the season;

3. should be able to set it to call (or not call) Time-out if the opponent scores _X__ # of consecutive points; this allows you to coach more life like and stop an opponent from blowing you out or like Phil Jackson let you squad play through saving you Timeouts for the end of the game; 

4.  Defensive rating is WAK, not functioning, problematic . . . the defensive rating doesn't matter enough, needs to be fixed;

5.  Should be able to designate by priority/prefernce who on your team will take the last shot (eg. buzzer beaters) at the end of each quarter and OT quarters;

6.  Defense is a PROBLEM  -- NBA teams rarely if ever full court press!!!  Should be able to trap (either below free throw line or whenever a certain player has the ball); and should consider adding zone defense option especially if you leave in press;

7.  Defensive needs to be fixed.  when a weak defensive player is put on a player who may only average 12 PPG, that players points should go up!

8.  Some players you have ranked too high in defense because they CAN"T play defense ... magic, charles barkley & larry bird all come to mind ...