Concerns about my new BP - Please help!

[Coluber42]

Insulation foam can go on the outside, not the inside. It's just thick foam board you can get at any hardware store, and if it's on the outside you can just stick it on with tape or whatever. (No tape on the inside!!!) You can also use styrofoam packaging, foam core, even cardboard will insulate better than glass, which lets heat right through.
If insulating it doesn't do the trick, then you should add a second heat source to boost the temperature on the cool side of the cage. If your substrate isn't very deep, this could be a UTH, or it could be an additional overhead heat source.

Any heat source needs to be on a thermostat. Herpstat is the favorite, but they're expensive; Jumpstart is a cheaper one that will also get the job done. The thermostat is really important, because without it your heat source won't respond to a change in the room temperature. For example, let's say that your room is 65 degrees right now, but when you get home you're cold so you turn on the heat until it's 75 degrees in your room. You've got your heating set up so that the cool side is 80 and the warm side is 90, in a 65 degree room. But when the room heats up and the heat lamp on the cage doesn't change, now your cool side is 90 and your warm side is 100. That's obviously not what you want. A thermostat will dim or turn off that heat source so that the temperature stays where it should even when the room temperature fluctuates.

For humidity, covering most of the screen top will go a long way toward raising it. But if you do that and the humidity is still to low, then you need another source of moisture inside the cage. Misting by hand doesn't do much for more than a short period of time because you're not actually adding that much water, and the little bit you add just evaporates right away. But your substrate can be a good reservoir for moisture, especially if it's on the deeper side. The coco coir stuff it looks like you're using is good for this; if it's a couple inches deep, you can even just pour water into it almost like you're watering a plant. It will spread out and soak in and evaporate up through the surface gradually over the course of a few days. Much easier and more effective than a spray bottle, unless you really like the hand workout.

The most important thing about hides is that the snake should feel like it's wedged in against solid surfaces. Snug-fitting hides are good; those half-log hides are not really that secure, although you can make it more so by partially burying it in substrate or partly filling it with moss, substrate, or wadded-up paper towels. Upside down flower pot saucers or plastic bowls or takeout containers can also make good hides, if you don't want to keep buying new ones as your snake outgrows the ones you have. Your tank doesn't look as empty as some, but some fake foliage or paper towel roll tubes might help your snake feel like it can move around without being seen.

Don't worry about your snake swallowing substrate along with its food. A bit of coco coir won't hurt; snakes in the wild swallow stuff that gets stuck to their prey all the time. And their digestive system is built to handle an entire rodent, bones and all, plus whatever's in the rodent's mouth or stomach. A bit of substrate won't hurt.