The bubble wrap FRS from Walmart are probably fine for what you want. You asked for help and don't want help, that is absolutely fine. When you have a radio with a bunch of buttons and several menus and different options you need to geek out a little bit, or at least nerd a little. Go bubble...
After reading @KQL post I think it was a privacy setting Notarubicon fixed. I believe he had to undo each channel individually, I could be wrong it's been a long time since I watched that stuff.
I don't have your radio so I can't give specific details, but a dude Notarubicon on the tube has made many videos on the UV-5R and how to set them up. This was a problem I guess like yours with the "new" UV-5R but he has the scoop on what to do. Probably gonna take some searching but he gives...
There's a bunch of after market switches made like the Lasfit and Voswitch and several others. I don't have experience with them because I have the factory aux switches.
Several people on the forum have installed the factory aux switches. If I remember correctly it requires a Jscan or tazer to...
More useless information on valve stem caps.
Aircraft tires use nitrogen, they use nitrogen because it is more stable with temperature fluctuations. When I serviced a tire I would have to take the ambient temperature and barometric pressure then look at a chart to adjust to the correct...
If your valve stems are brass go ahead and use brass caps. It's not a dissimilar metal and won't produce the galvanic corrosion. Get brass caps that have "o" rings.
FRS and GMRS share frequencies. You should be able to talk to anyone on a FRS with your GMRS.
This is convenient, although I paid for a GMRS lic and use a GMRS handheld I can talk to the guys that bought the bubble wrap Walmart FRS.
Use a quality DC to DC charger or a quality battery management controller on the 3rd battery. Camper and trailer people do this all the time. Tons of info on the Google machine.
Good luck.
Some of the online crap I've read said don't run pure kerosene because it doesn't have enough lubrication for the fuel pump, if you want a cleaner burn mix it 50/50 kerosene and diesel. Of course I bought a butt load of spare parts including a fuel pump.
There's some good information on them, some claim 8,500 ft. but who knows. There is lots of real world usage at higher elevation online, the biggest thing seems to be to keep it cranked up, or at least run it for 10 minutes on highest setting before shutting it down, you want to burn the soot...