Your electric heat will only be as reliable as the electricity itself. It's not uncommon for the power to go out in areas of New England for a few hours or even a few days. So prepare for that since it's a vacation home. For vacation homes, I usually recommend designing the plumbing to be pitched for easy drainage. When leaving you turn off the water supply (one valve), open the taps in the kitchens and bathrooms, flush the toilets, then go downstairs and open a single drain valve to drain the properly pitched supply plumbing. Then pour a bit of RV (NOT auto radiator) antifreeze into each toilet bowl and into each drain trap. Takes about five minutes, seriously. You could also plumb the new work with PEX instead of copper. PEX has a bit of give, so if it were to freeze the tubing won't be as likely to rupture as copper would. Also, no plumbing in exterior walls! Lastly, "smart home" technology has come a long way over the past decade. You can get thermostats that are controllable from the internet or a smart phone. You can get temp sensors that will notify you by email, or call your cell or home phone, when the temp hits a certain setpoint limit. Well, I didn't really answer your questions, but I just wanted to toss those ideas out to you.

1. For that much lighting, I would leave the circuits separate. 2. Check the installation instructions. I believe Suntouch requires a dedicated circuit. 3. The exhaust only needs GFCI protection if it is installed in the shower/tub area. This is not a NEC requirement, but is in the instructions. It can go on the lighting circuit. 4. Find a GFCI without the colored buttons (Cooper or Pass&Seymour) and use a Decora style for the other receptacle. If you decide to use two GFCIs, connect both from the line feed, do not connect one from the load side of the other.

John Bridge forum is an excellent option. I put in a cast iron shower pan, or rather had my plumber put it in. Then I used cement board, in this case Durock, followed by a topical membrane called Hydroban as directed on the product. I did not use a plastic sheeting on the studs. You do not use the plastic when you use a topical membrane. Then I tiled, using a nice modified thinset by Laticrete, and porcelain tile for the walls. Easy. The shower doors were planned ahead of time, and the reenforcing studs in place before the cement board was installed. All of the cement board was screwed in place and then thinset used to fill in the depressed screw heads. I taped the edges with fiberglass tape using thinset. After all was taped and dried then I used the Hydroban topical membrane. I love my Kohler cast iron shower pan, no leaks or disappointment with the grout on the floor getting stains. I used laticrete epoxy grout on the walls, and their color matched silicone caulking for the change of planes and at the floor/shower pan junction. Hope this helps. Hydroban in the shower area where the cast iron shower pan is. As you notice, it is very consistent in color in the wet area of the shower. Unlike the blotchy color of the wall near the cabinetry which is not wet area, I just used some of the Hydroban up by painting in that area (it was not needed). You don't want blotchy coverage. Tile over the topical membrane: finished shower with doors hung. There is heavy wood blocking at the hing areas of the glass doors: This is an alcove shower and is 36x60. I have the elaborate Hansgrohe rough-ins and fixtures. I have been very happy with them, but there are other systems that are quite good. I can access my valves from the other side, by pulling the cabinets seen in the first picture, I left a large opening in the drywall on that side of the wall, covered by the cabinets.

The tile is a killer since there is so much of it, and it certainly does make a statement. I'm guessing you're leaning towards a bit more traditional? So at a minimum? A low-budget "fix"? 1) I'd get rid of any stained surfaces (door/trim) and instead paint. 2) I'd replace the three mirrors with rectangular-shaped framed mirrors. and replace the light bars above the mirrors with sconces. 3) You can just replace the vanity as a whole. If that's too much, at a minimum I'd replace the vanity faucet. If you can go beyond that, I'd replace the hexagonal sink with a rectangular sink. If you can still go further, I'd consider replacing the vanity top too. I'd reface the vanity with drawers with frame and panel drawer/door fronts that more resemble the traditional 6-panel doors.All that', it's probably easier to just replace the vanity as a whole. 4) You can degloss and paint the shower frames to get rid of the brassy color. 4a) The brass and glass surround on the back tub could be removed and replaced with a curtain. 5) I'd consider covering the existing glass with a topical frosted film. Not sure if the existing design will shadow through the film. But look at different films, their levels of opacity, and see it it'll work. 6) New towel bars, etc, to get rid of the brass. 7) A large throw rug on the floor in front of the two pedestal sinks might disguise the stepped floor tile pattern. Good luck!