My grandma eats sweets including homemade pies with 1-2 c sugar per pie, loves sweets in general, eats too many fried foods for my taste, doesn’t eat paint chips, bathes in a porcelain tub, and was JUST moved to a nursing facility this year since she’s losing her mobility (mind is still intact) and in another month she will be celebrating her 100th birthday. You don’t have to live in a bubble to live a long life. Much of your life expectancy is predetermined in large part by genetics. Use common sense and don’t lick the bathtub.

Yes, the plumbing needs to be done first. Yes, you may be able to just get another acrylic shower wall to cover over everything, if the wall is not moldy or wet behind the tile that you are looking at. There is no need to replace the tub itself if it is in good shape, even if you do decide to take down the wall tile and replace everything from the studs out. Just make sure the workers cover the tub well to protect it while the work is being done. I am with Monicakm_gw, get some more bids for the work. You might want to have them bid on just replacing the walls with new fiberglass, and on doing the whole new tile job, too. You can see new walls at Lowes, Home Depot, and Menard's online. There is also the whole Marbleite wall option to look into. Local dealers for Marbelite are supposed to be cheaper than buying from big box stores, if I remember right. While you are fixing plumbing, you should probably put in a proper mixing valve to protect from scalds. It is the code now. No one will be able to turn the water too hot to burn themselves and flushing the toilet or using the water elsewhere in the house will not burn the person in the shower anymore, either. I have read the experts here on the forum say that the Symmons Temptrol system is very good and is a good value. Here is one that comes with the shower head and tub spout for under $100. http://www.homedepot.com/p/Symmons-Temptrol-1-Handle-Tub-and-Shower-Faucet-in-Chrome-S-96-2/100643619

"Isn't it funny how so many who have the tubs never use them yet when people look for a home they love seeing a jet tub in the master bath? Is it just the "thought" of that magificent soak we all wish for but never take that puts in our minds that we must have the tub?" Ditto with all the chef kitchens with professional ranges. In my area, hardly anybody cooks in their chef kitchen because everybody is too busy. OP renovates for resale, i.e. bang for the buck, which isn't necessarily primarily for functionality.

I’m not sure where your leak is coming from, I just wanted to tell our experience so you can gauge whether it might be a possibility in your case. One of our guest bathrooms had a leak that we originally assumed was from the shower. We hadn’t lived in the house for very long, and we hadn’t even used that shower yet when my sister came to visit. She stepped out of the shower and realized that water was squeezing up between the tiles when she stepped on them. Naturally, she informed us. My hubby had the entire bathroom completely gutted in half an hour! (It was a small bathroom with a Fiberglass shower, the tiles popped up like toast out of a toaster, and he’s just a beast... lol!) we see evidence of long term damage and provide my sister with another bathroom to use for the remainder of the visit. We didn’t start the bathroom remodel immediately, and when we did start it was slow going. We were very fortunate because we had barely started the remodel when we got another weather front move in with a whole lot of moisture... (It has been snowing a lot during her visit) and that’s when we realized the bathroom was leaking from another source! Hubby again ripped up the bathroom, and this time ripped out part of the wall that is on the exterior and that’s when we realized the leak was coming from outside. It took us a bit to figure out but we finally determined (with outside help) that it was because that wall was directly against an exterior chimney that had not been flashed properly. We left that bathroom unfinished for quite a while while we fixed the chimney problem, and waited for some more really good rain storms to make sure it was indeed dry before we finished our bathroom remodel. We were just fortunate that we have a lot of other bathrooms and this was just a guest bathroom. Anyways, I hope your issue isn’t something like that!