I started a "remove the carpet from the bathroom" project that snowballed. At this point, I've noticed several problems with the tub that I would like to address; This appears to be a standard built-in without any sort of "Bathfitter". I have access to a panel and noticed that the plumbing is not very secure (four nails sort of press against the plumbing to hold it in place), and the area around the tub is a wide open cavity. Also, the three piece surround is well adhered to the wall, but there the pieces overlap (five inches on each side along the back, they are not secure at all. 1) Should I put some sort of fill in the void around the tub for insulating? If so, would any loose fill work, or should I use Roxul? 2) Can the center panel be easily removed and reinstalled with the correct adhesive, or is taking it down going to destroy it and require me to get a new surround. (this would not make me cry at all). 3) If I don't have to take down the surround, then I can try to add bracing to the plumbing from behind. However, I'm not sure I can do that for the loose shower head. If I'm not tiling, can whatever hole I put in to secure the shower head be patched with drywall, or is that a cement-board area? 4) The tub itself has some sort of substance on it that tears apart my sponge. It's possible that the yahoos I brought in for an emergency ceiling drywall job spattered compound or paint on it. But it could have been there well before they did their lousy job. What sort of chemicals, etc. can I use to try to remove whatever is there without damaging the coating of the tub itself? Thank you,

What are my options if there is a leak at one of the tank bolts and when I tried to tighten it,the head of the bolt cracked off?Can I get the threaded part out of the tank?