Hi, Stotty, sounds like he's still settling in - hope he feeds for you soon but you know what royals can be like - awkward eh?
His temps should be 26 cold end, 32 warm end. I'm afraid I don't measure humidity but I use vivs - if a snake's shedding I put the water bowl in the hot end and that works for me, so I'm not an expert re humidity.
Being lazy I don't lower temps at night - some people do, some people don't. And I've noticed many snakes like to go into the warm end after feeding, so personally I wouldn't lower temps below what they need to be, but that's just my opinion. (There may be a natural night time ambient drop anyway, especially during this glorious summer weather - not!)
How long has he not eating for o had mine for 9 weeks before he ate anything I think they can take a while to settle in keep an eye on his weight to see if he loosing anything. I took mine to a local pet shop for them to check on for me. I was reasured that he was ok when they looked over him for me plus tried to feed him for me. He didn't eat with them either but they were prepared to check on him regulary from there on and even assisst feed him if necessary If he continued not to eat with me.
I chNged his food from mice to rats etc and he took rats weavers in the endwhich I thought where to big for him but he loves them