The neutral wire will be marked if at all. There will be a dashed line printed on it or raised bumb. Look for any differences between the two.

Yeah, that's not how things work. Do it right or don't do it at all.

In all my years I have never seen a paint that covered in one coat. I've tried the paints, the rollers, it doesn't work. It's close but it doesn't work. Just grab another can and put a second coat on it and be done with it. What looks good now won't look good tomorrow morning as you discover new areas that need a touch up. Then another. Then were you cut in stands out. My standard is prime, then paint 2 coats. Rarely have I ever had a problem.

No one is born knowing everything. You have to learn it somewhere. Some of us just get to learn it the hard way.

Woah, pump there breaks there. If you plan on selling after the reno or even shorty afterwards, do not go nuts with the smart devices. You could spend thousands of dollars that you probably won't get back and depending on who buys it, probably won't use most of it.

I would limit myself to USB receptacles in bedrooms and kitchens, maybe hard wire security cameras. Beyond that, understand that you are doing it for yourself and probably won't get your money back out of it.

Some places people are forced to have their washer on the main floor. People don't like looking at a washer and dryer all of the time. The cabinet is purely for ascetics. You might get a bit of sound dampening but it's not the point of the cabinet. Feel free to remove it if you don't like it.

For a heated floor make sure you use a stone like ceramic or porcelian tile. Tile will have a high thermal mass and take a while to heat up, but will also take a while to cool down. It's only natural for a heater to cycle on and off as it maintains a set temperature but a tile will hold it's heat for hours.

While you can use certain laminates or vinyls for heated floors, they have low thermal masses and will heat up or cool down quickly.

It's the same reason we use bricks for houses. The brick would absorb the heat from the sun all day long and at night it would radiate the heat into the house all night.

The bottom line is you want to ask the manufacture of the product you want to buy if it is acceptable for over radiant flooring systems. Anything other than that is just guess work from everyone else. The manufacture will give you a definite yes or no.

That said, I wouldn't really recommend it. I've done a laminate floor over heat that was cleared by the manufacture, but there isn't much thermal mass there. The floor got warm but it didn't really feel warm.

The benefit with a tile floor is that while it takes a while to heat up, it holds the heat. When you walk on it, the floor feels warm. If you put cold wet shoes on a vinyl floor,they will suck out all of the heat in the area and the floor won't turn on unless the sensor is in that area.

That's just my personal opinion. I'm not saying it's wrong but it depends on what you expect to get out of it. You might be just as well off wiring an electric heater on the wall and calling it a day.

That's just the base model. Larger units and extra capacity is available.

Honestly, like everyone else has said, building a backup battery out of cells isn't the best place to jump into DIY with little knowledge about electricity.

What I would recommend is something like this.

https://ca.ecoflow.com/products/river-portable-power-station

You can charge it from solar or the grid and provides you with 5v, 12v and 120v and probably cost less than what it would take to buy the cells, let alone the equipment and parts you need to assemble said battery.

If you want to get into battery building, start with repairing cordless tool batteries. You only need 5-10 cells, not 260 plus. That is asking for a fire.