I have tiled over ceramic tiles, but NEVER over large cultured marble panels. Any thoughts on doing such? Thanks, Dale in Indy

Ok so I have a bathroom that is rectangle and is 60 1/4 inches wide finished drywall and all etc. The current tub / surround is mounted to the finished walls & measures 60 x 31 The new tub will measure 59 x 32 x 24 (tall) with removeable skirting. Without the skirt I estimate the tub at the edges is about 2 inches thick. So with all the testing, measuring, re-measuring etc. In my head I see myself standing the tub on end to get through the doorway. Then getting it into the corner and bringing it down flat to lay in place. The tub being only 59 inches long and the finished room being 60 1/4 wide. I shouldn't need to cut any drywall or anything. I should simply be able to slide it in place and lay it down and level it off. Anyone had an similar experience or see anything wrong with this idea. I also have another issue I want advice on. The tub/unit I am installing is a full tub/steam room unit. So its plumbing is actually separate from wall mounted plumbing. I need to remove the existing diverter and faucet/handles and shower arm etc.. and drop the water pipes down and bring them up through a different hole in the floor. So they are no longer running into the wall cavity. I also will have a emergency shut off valve accessible behind the skirt of the tub for both lines. That being said. This plumbing has no access hatches. BUT I still need to get at the back of the plumbing to remove the faucet and handles and a way to unscrew and remove the shower head arm. My thoughts were to cut a small hole in the bathroom wall beneath the faucet/diverter and remove it. So I am making an access hatch on the facing wall not from behind in the adjacent room. Then I am thinking of simply cutting the shower arm and pushing it back into the cavity since I won't need it anymore. Then I can simply cover the hole it left. Once I remove the faucet and handles I can cover the holes it left and that should effectively clean up that wall and plumbing. I will now have hot/cold pipes free to reposition somewhere else under the unit. Anyone have any advice on a better way to tackle this portion of the job. Remove the old faucet and shower arm without cutting a hole in the wall is ideal. The absolute easiest way I can think of is to cut the pipes below floor level to make moving them easier and then just remove the handles and spout and push the entire thing into the wall cavity. Same with the shower arm itself. Unscrew the outer cover and push it entirely into the wall cavity. I am just not sure how to remove the handles and spout. They all seem to be a solid piece and non-removable. I guess worse comes to worse I can just break them off. Then I can patch small holes and be done. Just leave the old plumbing loose in the wall. Since it is no longer hooked to any live pipes it will just sit and gather dust. Is there any real reason not to just push the old fixtures into the wall cavity and leave them? I mean I don't plan to ever use them again. This is a manufactured home so I am betting the entire faucet piece itself is 3 connections hot/cold/shower arm and no separte diverter is mounted in the way anywhere. So pushing the piece back into the cavity should be easily done. Thanks for reading my very long post & I appreciate all the advice.