It all depends on what they used to install the tile and the condition of the concrete. Best case scenario was very smooth/shiney concrete with a non-modified thinset mortal, which the tiles pop easy and the thinset can be scraped with a standard flooring scraper. Worse case scenatio was rough concrete installed witha modified mortar. Tiles come up in little pieces and the thinset is now a part of the concrete where you take off the high spots and feather it out with floor patch or you need to grind it. There is middle ground if the concrete was shiney and smooth and they used modified mortar. Do a test with a hammer and cold chisel to see how easy it will come up and scrape. If its very tough, go rent a small demolition hammer with a 3" scaling bit.

I do not think Lowes will do the install. What you may consider is having a tile person "trim" the tile so it can be installed as usual. It's either drill or cut.

A copper soaking tub might interest you. Ceramic isn't nearly as durable as porcelain. I'd keep looking to find both wall and floor tile that is all porcelain for such a heavily-used area as a bathroom. You don't need contrast with your floor in such a small space. Keep it all the same pattern. We just redid our master bath with Happy Floors porcelain tile in a marble-look pattern and are thrilled with it. You can't just move plumbing like that. The whole shower drain through your foundation would need to be re-routed not to mention that wall being gutted to the studs and likely other foundation work for tubing additions. You might as well build on a new bathroom for what that hassle and expense would cost you.

@ci_lantro Yes, the tile is falling off the wall the further up to the ceiling it goes. Will have to be redone. I did do the stick test and its very substantial at the top. @Creative Tile Eastern CT I agree. My thought would be to have the schluter trim before tile adhered to wall but my installer said he installs that after and slides it under. I think that still has potential for gaps behind tile where no mortar is. Since the top few rows need to come down because they seperated from the wall, I will take a look at how the mortar coverage was applied. Thank you all for the suggesstions and comments. This little shower project has turned into a much bigger headache.I will have the installer fix the tile seperating issue and hope to have this completed properly soon.