I'm just going to touch on the parts about whether it will work. I'm 48 and perimenopausal so my metabolism is slow. I don't exercise very much beyond physical therapy and walking because my back is messed up. When my back was better, I saw a number of personal trainers. They helped me get in shape, but not lose much weight.
I've found it relatively easy to lose 34+ lbs. in 2 1/2 months, much faster than on any other diet I have ever been on.
I'm rarely nauseous and I've thrown up 2x since I got the surgery. I was very adept at using 2 oz. cups to make sure I didn't consume too much when I was healing. Now I eat pretty normally, just a lot less, less carbs, and more protein.
I think WLS has changed a lot and some people have ideas based on older types of WLS surgery that weren't as easy to live with.
Whatever you decide, good luck!