OK, my two cents for what it is worth...

You're a bit limited with this roster in terms of flexibility.  You have one guy redshirting and one guy (Frazier) who is definitely not ready to play yet, so that leaves ten players.  Of them, four have single-digit REB ratings and so can't play anywhere but guard.  Four more have low SPD and single-digit PE, so they can't play anywhere but PF or C.  That leaves Haas and Spellman as the only potential SF's.  (Don't let Haas' low REB fool you, with his edge in ATH over Spellman he is probably almost as good on the boards.)

Haas is your best overall player, and based on the fact that only two guys on the roster can handle SF, that's where I'd start him.  Spellman should be the top backup there.

At PG, Bruns has the best skills - but O'Brien isn't bad there, either, and even Gray can play it in a pinch.  Rowley isn't ready for minutes there yet.  Since he was promised a start, he starts at SG.  Otherwise for the guard rotation, I'd consider where the opponent has a scoring threat because Bruns is the worst defender.  Given that he is your best scorer and your worst perimeter defender, you don't want him getting into foul trouble.  So I would play him at the guard position where the opponent has the least threatening offensive player (will change on a game-by-game basis).  If he plays PG, O'Brien backs him up and Gray backs up Rowley.  If he plays SG, then O'Brien runs the point and Gray backs him up.

IMO, your best offensive frontcourt player is Holiday.  I would start him against the weaker defender among opposing big men.  Albarado is the weakest defender, so I would play him against the less-threatening offensive player among opposing bigs (you can see that I mix and match a lot!).  So sometimes Albarado will be backing up Holiday; other times he will start alongside him.  Vance and Dube are interchangeable, nearly identical players except Vance is slightly better on the boards.  With that in mind, if Holiday and Alvarado are both starting, I'd run Dube at backup PF and Vance at backup C.  If Alvarado is backing up Holiday, then start Vance at the other big position and back him up with Dube.

I realize that is a lot more complicated than simply giving an all-purpose depth chart, but I think it is the way to maximize your results - plus it is kind of fun! 

Given the promises you've made, you will probably need to sub by target minutes instead of fatigue.  That way, if Bruns is your backup SG you can still get him lots of minutes, and you can try to get Frazier just enough minutes to keep him at Wisconsin Lutheran without costing you games.

Distro-wise, again it should be opponent-dependent.  But in terms of the quality of your scorers...

Top guys: Bruns, Haas, O'Brien
OK and best frontcourt threat: Holiday
Mediocre, low distros unless a great matchup: Rowley, Gray, Spellman, Dube, Vance, Albarado
Garbage buckets only: Frazier

Good luck!  Hope it works out!