Yeah, I have to think that the one area you do NOT want to fuck up is a wet zone like a shower/bathroom. You'll want to have done solid research and planning. lol
I like thinking of all the things I’d do to fix up this house, but it usually ends with me thinking “well, shit. We’ll just buy a new house.” We’re really glad we closed on ours when we did (3.125% on the mortgage, and two weeks after it the rate was 7%). But it does need some work. Luckily, I grew up in a house literally built by my parents from the ground up, which was an unending project and definitely not up to code. So I am patient about it all. I consider having actual shitty carpet floors, and not painted subfloor, to be a win.
I get what you're saying. That's exactly what I demolished and replaced, a tub with no option to shower in it. They're so dumb, who still soaks in dirty bath water? I thought about doing a glass block window where the old window was. I decided not to because of my budget and added complexity. It would have added about $800, and added a weak point for water intrusion. I will almost always choose robust and simple construction over adding things that may cause me problems later on. It will depend on what you find when you take down the walls around the tub. Best case scenario, you don't find any soft wood or mold behind what is currently the walls. Then, yeah, a little plumbing, cement board, roll-on water proofing and tile. I had some springy/flexible subfloor under the old tub. Just a very little bit of mold on the sheetrock, which I was expecting from a washing machine leak on the other side of the wall. I was actually expecting more mold than I found. That leak is what ultimately got this project moved to the top of my list. I removed everything with any sign of mold, and treated all the framing, even though it didn't show signs of it. That also might be an issue with the tub only setups, there was absolutely no waterproofing done in that alcove in our bathroom. I guess the expected people to not splash any water outside the tub. There wasn't even water resistant walls from the tub to the ceiling. It was just sheetrock. Hopefully, you find good news when you start to demo.
We're in the same boat. I love our home and I can't even imagine any circumstances that would get us to sell and move, but we're also stuck here because any home we could afford in today's market would be levels below what we have. Unless you buy a new home with a warranty, you're going to be fixing and upgrading things. Might as well do it without paying high interest rates at the same time.