Here I am again with my noob questions...

First, the soiled substrate. I'm currently using paper towels and I've had my ball pythons for three weeks now. Some of them have eaten, some haven't. It's been 8 days now since my last feeding effort and I was thinking of trying again today. I've got four little babies who haven't eaten with me yet, however they have eaten live mice with the breeder. I've tried F/T, which the other babies have accepted readily. My actual question is about the upkeep of the enclosures (they're all housed separately in small rubbermaids, my plan is to sell them as soon as they've had their meals). Of course, soiled paper towels need to be replaced right away or as soon as possible. However, will this disturb them so that they might not eat? I had to take them out of course, take everything out of the enclosure, then change to clean paper towels, then but them back. This took perhaps three minutes, during which I put them in a small, plastic, ventilated box. I tried to handle them as little as possible.

Any tips on how to be as discreet as possible with the cleaning? Will this stress them and is it advisable to really leave them all alone during the feeding efforts (I've replaced the water every two or three days or so, but the paper towels are harder to replace without causing disturbance) and not change the substrate?

My second question concerns one of the females. She's very tiny and hasn't eaten yet, her skin is also kind of loose, but her eyes aren't dented and she's been really active during her stay here. When I got her I noticed her nose looked different than the others', it seemed dry, it wasn't as shiny as the rest of her scales. What could this be? She hasn't yet shed with me so I don't know if it's permanent. Here are some pics to describe what I mean:







It's not actually gray, that's the lightning playing tricks.