bullnose tile on shower wall

i am wanting to put subway tiles on my back splash. just a basic brick type pattern. how should i center the tiles between a window and the corners ? as in. full tile on the window side and let them fall where they may on the corner side = half/quarter/third/whatever, tile to the corner. or center them in the space, and have partial tiles on each end ? also. the electrical boxs. i know i should get extensions. but i found that unscrewing the switches/outlets them come out far enough that i can fit the tiles behind them. i prefer this, as putting in the extensions will and a bunch of work. and going up to the bottom of the cabinets. i know the correct way would be to pull the cabinets. cut reliefs, tile and hang the cabinets. but this would be a lots more work. or. cutting the tiles to fit up to the cabinets. again, a lot more work. but i am thinking. that because the area is not really seen i could go up close to, but not flush with the cabinets, about half a tile. and leave a little of the wall exposed. ? the above range microwave. i can go up to it. but should i stay down from it a little ? thanx guys.

Bathroom has a garden tub that I want to take out and replace with a shower. The problem is that there is a glass block window/halfwall at one end. With it of course is various pieces of trimwork that are fine in a tub environment but would be a disaster in a shower. I much prefer not having the window filled in and converted to a wall, as this would involve far too much work, what with the hardiplank exterior and the window being quite high off the ground. To make things more difficult, the builder thoughtfully positioned the window so that they could turn the interior sill into a conventiently placed shelf, which will be guaranteed to turn into a nice pool of water with a shower running. In addition, the window is not centered in relation to the shower and extends beyond what would become the shower wall. My preliminary plan is to tie in to the glassblock by constructing a short floor to ceiling glass block wall at right angles to the existing window/wall. The problem is what to do about potential moisture problems because of all that trim work that has to come out. I'm thinking of replacing it with exterior grade manmade products (picture smooth finish Trex planking) but how can I make sure water runs off and absolutely cannot get behind it?