Rough Skin and Sharp Tail

I have an almost 6 year old albino corn snake who I have had since she was 3 months old. I've never had any major health concerns - she eats well and her sheds are usually in one piece.

Unfortunately during her last shed (about 2 weeks ago) the skin came off in pieces, so I soaked her to remove the pieces. A couple days ago I noticed 2 things - first that she had a sharp (pointy) tail and second that she had a rough patch of skin that looked like it had been scratched on bark (but there is nothing like that in her vivarium).

So I though maybe temps were off (I use a heat mat). So I ordered an infrared heat gun to double check the accuracy on my digital one. I also ordered a thermostat (which I never used before). Today, I got the temps stabilized to 86 on the warm side.

But just to be safe, I took her to her vet (specializes in reptiles). He didn't seem concerned about her tail - just that it was excess skin that wasn't hurting her. And her rough skin could be due to the bad shed and just looked irritated, not infected. He recommended some soaks and raising the humidity using a humidity box.

I used a plastic igloo (made for hamsters) and I filled it with damp papertowels. Also, I spritzed some of the walls with water.

• My concern is how to make sure I do not get too humid and cause an RI. And when should I see a humidity rise by? Right now, my probe says its 23% which seems really low so I will buy another incase this one is faulty.
• My other question is: does that make sense about her tail?

Thanks for any help!

I just got the vet notes and he referred to the tail as having a "keritanized cap" if that helps.