Just showed up to coach at Missouri State in D2 and I find this guy as my only point guard on the roster. 

http://whatifsports.com/hd/PlayerProfile/Ratings.aspx?tid=0&pid=2615604

I have very little experience at D2.  Does this guy's defense basically make him unusable, especially considering I am running man to man D?  Or do some of his other attributes make up for it?

When I take over a team I look at the ratings to see if they would be useful, but I also look at the class the player is in. In your case I would ask the question do you want this guy taking up a spot on your roster for the next three seasons because if you do not cut him that is how long you are going to be stuck with that particular player. 
With such a low ATH and DEF combination it is my opinion that it would be best to cut him.

Agreed -- I'd cut him.

And I'd cut Shelton and Thomas, too.

Crowder's no great shakes either. I'd cut everyone except the seniors...and the only reason not to cut as many of the seniors as the AD lets you is coz they are gone after 1 season. They mostly suck too. This way team is full of your own guys by next season...

What I don't want to do is spread my recruiting dollar too thin though.

walk-ons (1 season then gone) and getting the cash for them next season is better than carrying these guys for 2 or 3 years.

In a rebuilding situation, you don't have to fill all the spots.  You're not going to win anyway.

If you cut 3 players and recruit 5, you'll have 9 players for this year.  You can maximize your freshman growth by giving them as many starts and minutes as possible. Next season, you'll have 7 openings. Again, only fill 5 or 6 of them.   You can go for a full roster in the season following that

whatever you do, please don't cut the cheese!