So I had my idle air control valve off to check to see if it was clean, because i've been experiencing a bit of a rough idle lately. I noticed that the hose that goes between the idle air control valve and the vacuum tube has an inch long split in it.

I'm assuming that boost would easily blow out of this line, but what else could this cause? Would it make the car run rich as well?

 

Yes it will make the car run rich. It is unmetered air.