welcome!
just some tips based on what i'm seeing and reading:
go to walmart and get a digital temp/humidity gauge.
tape tinfoil over the mesh top (no tape inside), cutting out a hole for the lamp, to trap humidity. another tip i use to boost humidity is to wet a hand towel, ring it out so it's not dripping, and lay it over one of the hides. this should boost humidity for about a week before you need to rewet the towel. also, get some sphagnum moss: that stuff is great for humidity.
get some fake leaves and vines to clutter the tank a bit. the enclosure looks very open, which makes the snake feel vulnerable, which may be why you're getting hissed at. side note: don't back off when you get a hiss, and try to pick them up anyway. 99% of the time it's a bluff, and the snake needs to learn they won't get their way by hissing.
i'm only seeing one hide, and it's open on both ends. you should consider getting two cave-like hides with only one opening.
no need to drop temps at night. keep it consistant.
ALL this being said, the fact you have a thermostat shows you've actually done your research! your on your way to many happy years with your new legless child.![]()