Converting tub to shower. Issues with window in shower.

My home is a four piece modular colonial. The bottom two pieces have 2x6 ceiling joists. The top two pieces have open web floor trusses. There is about an inch-and-a-half gap betwen the 2x6 ceiling and the floor trusses above. That is, the floor trusses make NO contact with the 2x6 ceiling. I discovered this setup when addressing a second floor water leak, which was a long-term problem repaired repeatedly. I felt it was time to investigate the possibility of mold growth due to the water leak. I opened the kitchen ceilng and found that it was 2x6 and faced with OSB on top. I opened the OSB and found that there was nothing resting on it. The only contact points between the first and second floor are at the center of the house and at the edges. Sounds to me like an opportunity to raise my 7 1/2 foot ceilings. I would like to put in coffered or tray ceilings throughout the first floor, maintaining the original ceiling height at the edges of each room and raising the centers in a stepped fashion by three inches per step so that the center of each room is at a more normal 8 feet. The question is "Should I?" I believe that the 2x6 ceiling serves only to hold the rim joists in place and keep the center beam from shifting side to side, but carry no weight but their own. I like the idea of the dead space between floors and intend to maintain it by not attaching the raised ceiling to the floor trusses, but to a structure that would be built between the trusses and would make no contact with them. This keeps sound transmission between the floors WAY down. Are there issues I have not considered? I have posed this question to the modular home manufacturer, but thought I would throw it out here as well while I wait for a response (been waiting two and a half days for a response already).

Hi all, We've got about a dozen holes cut in the wall from an electrician who installed some LEDs for us. He did a pretty good job of keeping the cutouts for us. A few he couldn't save or fell in the wall, so I had to cut some new sheetrock for those. I've attached some example photos. First - Ceiling (yes, there are two different colors in this pic) Second - Wall Some questions. 1. For the holes that I managed to replace the cutout, which contains knockdown texture and paint, would it look OK to simply spackle the cut lines..sand and paint? Or, should I sand the texture down on those and the surrouding area, apply tape and compound and then do new knockdown texture and paint? 2. For the new sheetrock plugs, I'm thinking I should sand down the texture from immediate surrounding area to match as close as possible the new wallboard, then tape, compound, texture and paint. Sound like the best method on these? 3. Since the areas are pretty small (3" x 6" biggest), I thought I could do fine with getting some knockdown texture spray in a can from Homax. I know this isn't ideal or the professional way, but for this purpose and the fact that I've never shot texture from a bin...I thought this would be OK. I also heard the best thing to do with the can sprays are to warm the bottom under hot water for a minute or so...then shake well and practice on some cardboard or spare wallboard. Thoughts on this method? While I have some framing background, I'm a novice at this stuff and would like to keep it as simple as possible to lesson the mistakes that would look obvious. :confused: Thanks! P.S. The cutouts are screwed into 1x2 backing strips, done after learning about that neat little trick.