Looking at your last picture I see those studs were put in after the flooring, which means this house was sealed up before this short wall was installed. Also looking at the first pic if this was structural you'd see 2x8's laminated. This is drywall framing to bring down the size of the door to normal indoor specs. Something held the wall up while the flooring was being installed...

If if were mine I would put temporary jack support in the doorway (threaded type) and apply light pressure. Knock that wall out. Gently lower the support and observe the above brickwork. It should not move at all. Then I'd reframe the door with fresh 2x8's to give myself a nice nailing surface for the trim when I'm done and adding more strength to the doorway.

I'll back him with 25 years of automotive servicing experience. White grease is great for things like where a steering shaft exits the body through a rubber boot. Or power seat mechanisms where it won't react with the rubber and quiets the movement. But it will harden, and it collects dirt and dust and hardens to slightly crusty, hard "wax". This takes years but it will build up if continuously applied. The biggest problem area on cars is the hood latch; Shops spray the latch thinking they're lubing it. They're actually helping fill the latch with dirt and that causes them to not work. I remove the latch, clean it in a varsol bath, and lubricate it with a light oil. Fixed.

In controlled environments like inside a car, or inside a machine, it's great. Garage doors are outside. I'd use it on the overhead spring because there's nothing there to get jammed up. But not the wheels. 3 in 1 or Light Machine oils.

There's no "Universal" set but what you can find is what's called "Slip-joint" or brand name "Channel-Loc" pliers. They'll fit pretty much anything. Vice-Grip is another brand but the teeth on them are very sharp. Great for removing, not so good for installing.

Piece of cake. 15 minutes to swap and we do that all the time. You want to find a "showerhead kit" like this one. Then you'll unscrew the existing showerhead. You can see the teflon tape on your current shower head? Using pliers you grab the old showerhead on the larger-diameter portion and turn counter-clockwise to unthread it.

You also need a small roll of Teflon tape. You'll put 2 wraps of tape on the threads of the shower pipe and thread the new shower head on. Tighten fully. If you need to use pliers to tighten put a towel between the pliers and the new shower head to help prevent scratches.

Drilling a hole in a french door... not something I'd recommend for a solar wire. The door wont care and you say not openable so if it's in worn condition then sure you could. Did you verify the door is wood not metal skinned?

A cap for a hole like this would be an easy 3D print job. Or you could get a 3/4" dowel and cut your own plug. Put a little door knob pull on it and you could insert & remove as needed.

"Modern dimmers are built from semiconductors instead of variable resistors, because they have higher efficiency. A variable resistor would dissipate power as heat and acts as a voltage divider. "

Is this quote not true? Were old ones were not resistor types that induce voltage drops?

Agreed! 5k is too cold for us too. I bought a handful of 4500 or 5k bulbs from the local Orange store and put them in the outdoor fixtures of my rural home.

Terrible. Cold, stark white like an operating room in the middle of farm land. Swapped them out for 2700k and lower "wattage" and they're much better. I tried the bulbs in the fixtures in the house but again the only place it was decent is the basement workspaces.

Worth noting that old style dimmers with turn knobs and slider-paddle type are a variable resistor and induce a voltage drop. These are still for sale in stores today and some LED bulbs will work with them, but some will not.

https://en.wikipedia.org/wiki/Dimmer

Doesn't matter. He's making good money without school debt. If he doesn't work hard someone else has to because that work still need to get done.

Ikea sells a clean cable-hide track that has a removable self-adhesive. I used it for a horizontal run to my 3D printer. It tucked right into a curve in the floor trim to the point it disappeared from view

Edit; Found it: https://www.ikea.com/us/en/p/montera-cable-management-white-30147425/