I've added shrimp recently after having my blue throat in my tank for 8 months. No problems at all.

I read that they make grunting sounds? is that true?

Don't know about grunting sounds but I have seen mine fart.

Never heard any sound from mine.

http://reefkeeping.com/issues/2009-04/fish/index.php

under notes.

I heard mine grunt when he was in the bag but never in the fish tank.