Welcome to BP.net!
I use newspaper as substrate for my BPs now, and feed them in their tanks. It's much easier for me than having to pick them up and move them, especially right after they've eaten. Typically all I do is take some tongs, dangle the rat/mouse in front of their hide, and they'll hit it.
UTH needs to be on a thermostat. ReptiTemp 500r I think it's called is what I use. Since you only have one snake, I'm thinking that or something similar would be your best bet, something meant for just one snake.
Humidity--did you buy one of the round hygrometers and thermometers that stick to the wall of the tank? Those are no good. You should buy one with a probe. Some stores have combo hygrometers/thermometers for around 25$, and it has a probe you can use. It's much more accurate.
To get humidity up, you have a couple of options. A lot of it depends no where you live and how the normal humidity is.
Where I live, the humidity is almost nothing, so I use the screen top duct tape treatment posted as a sticky here in the forum. You could also supplement saran wrap instead of duct tape.
That still doesn't get the humidity up for me, but helps keep in what I put in the tank. I spray with a water bottle 3 times a day, and also make a hide box of sphagnum moss. You need a tupperware container, and you need to put a hole in the top for the snake to get in. Put in the dampened moss, and the snake can use it as needed.
It soundsl ike you've done some good research. Good on you.