No experience with Aurora gobies, so I can't help there. But I have the Shrimp Gobies issue of Coral magazine and according to it Cryptocentrus
gobies should be paired with Alpheus
shrimp... you your pairing should be good. They do warn that the goby should not have a concave midsection (aka be skinny) or you run the risk of the shrimp eating it!
My experience with a Yellow watchman/tiger pistol pair has been good and I think you'll enjoy the character they'll bring to your tank. As far as rock slides go... if you have a solid rock base that has good contact with the bottom glass you should have no troubles. However, my shrimp has occasionally buried corals placed on the sand bed or even moved them to incorporate into cave openings. I've never lost anything due to these activities.
Another consideration with adding a shrimp/goby pair is sand bed biodiversity. Very rarely do I see the shrimp capture any food during feedings. I do see it occasionally eating algae off of the LR
but other than that I'm assuming its eating sand bed critters. May be related (or may be not) is the fact that my sand bed has no bristle worms or other macro sand bed hitchhikers often seen in established reef tanks. A lot of this may have to do with the area/volume of sand bed so large tanks may not experience this. Also, I don't think it has ever attacked or killed any snails, starfish, ect. I've purchased and added to the tank.
Oh, and as far as seeing the shrimp... mine spends 99.9% of the time in it's network of tunnels. I see it a couple times a month (at most) and that's often just an antennae poking out of an opening or a flash as it darts back into it's cave. If I don't see it for a few months then the snapping sound lets me know it's still alive and kicking.