So I got my first snake on Saturday at the Reptile Super Show in Pomona. He's a male BCI, born 3/26 last year. He's approximately 26" long and weighs 109 g. I'm absolutely enamored with him and it's taken all my willpower to leave him be and let him settle in. I have him in a sterilite underbed storage box (I think 76 qt) with a CHE, and flexwatt regulated by a VE 200D.

That being said, I have a couple questions.
1. Does he seem small for a 9 month old? I included a pic of his feeding records. I haven't fed him yet, going to on Saturday.
2. I have a temp gun, his belly heat is 90 on the plastic and about 88 on top of his aspen shavings. The ambient temp on the warm side (which has the CHE above it) is 81, but the ambient temps on the cool side is only 73. So, my question is, how do I warm up the cool side's ambient temps? Should I buy another heat lamp with a CHE and put it above the cool side?
3. The humidity is hovering at 75%. I know that's too high, I've drilled more holes in the tub. Twice. Should I just keep drilling holes until I get it to lower like 10 ish%?

Thanks guys!