If you already have a pressure washer. You can buy a "Clog Hog" drain snake for it. They really work well and are worth the investment. Save one Roto Rooter call and you've paid for it. Do a search for "Clog Hog".
I have the same ceiling in my basement rec. room, installed about 50 yrs. ago. I had some water stains like that and had pretty good success sealing the water stain area with a sealer shellac (to prevent the stain from bleeding through) and then painting with flat white paint.
Wiring diagrams are usually included with the LED tubes. And yes watching a few "good ol' you tube" videos is always a good idea. LED tubes are not all wired the same.
Eliminate the ballast and install direct wired LED tubes; reducing your wattage per tube from 40 or 32 (depending on age of Flor. tube) to 18 watts per tube. Also you could replace the whole fixture with a suspended 5000 lumen LED for about $20 and really light things up. I hung one over my...
There should be a weep hole in the bottom of the meter socket to drain away any water that may get into the socket to prevent exactly the problem you are having. Is it per chance plugged with dirt or the like? Speaking from 35 years of IOU meter experience.
May be the flame sensor. Could just need cleaning. Our dau. had this problem. Furnace would not come on in morning then by the time she got home from work it was fine. Turns out the flame sensor needed cleaning and her nice repair guy even showed her how to do it. In the morning when everyone...
I would avoid HF compressors. A friend of mine brought one to me that didn't work. It looked fairly new but wouldn't pump above about 10 psi. I totally disassembled it and discovered that the compressor piston/cylinder is very cheaply China made. They do not sell any repair kits or parts at HF...