I have allotted 100 minutes between my five starters, but I have two or three guys off the bench who I give 19-23 minutes a game to. Do I need to give my bench guys a # so they get plays ran for them? Or does the CPU know to do that when my 25% guy is on the bench? 

You should do minutes by fatigue, not target. Target is really an inferior method.

I think he's actually talking about distro...  In which case it doesn't refer to minutes but how many plays will be run for the player on offense.  And you need to give some to your backups if you want them to take more than a few shots here and there.

if you are truly talking distro, if you leave a player at 0 not only will the engine determine when he shoots, but +/- 3 pt settings won't be implemented, even if you change them...

dac, that's only if you leave EVERY player at 0.  If you leave 1 player at 0 he'll just very rarely shoot.  Don't know about the 3 pt settings, but the one time I left a guy at 0 instead of 1 he only took about 1 shot for every 15-20 minutes of court time, so whether it was a 2 or a 3 wasn't awfully important...

" if you leave a player at 0 not only will the engine determine when he shoots, but +/- 3 pt settings won't be implemented, even if you change them..."
Not true.  I left my entire team at zero for the whole season but selected three point shooting.  I chose three +2 playes and they shot about 95% of my three pointers and the -1 and -2 players shot zero threes.