Hi! I’m pretty new too and this is my first BTS but he’s a northern and does seem to enjoy his humid hide, it definitely has helped with shedding and he’s sometimes ended up crawling in and sleeping there between sheds too. It also doesn’t put humidity too high in the enclosure in general.
With UV, there’s a lot of posts on it, but as far as I know there are two ways of doing uvb, either as a strip light separate to the basking light or in an all in one MVB (mercury vapour bulb). I’ve gone for the strip light and then having the basking lamp separate. With this way I’ve ended up trying a few strengths of bulb for basking so it’s sort of trial and error with that, but with the recent heat it’s a 40 watt bulb (any household bulb works fine) on a dimmer thermostat and seems to do well. There are lots of people with more experience and experts who can give proper advice and the difference between the two but that’s just how I have it set up at the moment and it seems to be working.
As far as fires go I don’t have any advice, I have mine on a timer plugged into a surge protected extension lead which stops electrical surges causing problems but that’s it. Also I’m in the uk so not sure the differences in the UK and US when it comes to that.