Trans. mount gap?

[A_+]

I've had a knock/vibration coming from under the car for a LONG time and I just got around to removing the crossmember for inspection. The crossmember itself is in ok shape, the driver side that connects to the car appears to have been bent a little to better accommodate the exhaust but I think it is still touching and causing some problems. Anyway, I have two questions.

Is there a method to removing the mount? The bolt just keeps spinning!

Also, upon inspection I noticed this gap. Is that normal?

I probably could have cleaned it better but I just washed up

 

[CC'S95GT]

the head of the stud is supposed to be tack welded and that's what's broken thus allowing the nut to spin.

 

[A_+]

Thank you. Yeah, they're both spinning and I can't remove the nut on either. Anyone know the size of that thing, just in case I can't pull this one off?