1) How exactly would the skitter remove the guy in the first pictures tight jeans?
The skitter would have to use its claws and jaws, would probably have to rip up the clothing to get it off.
2) What will it do with both guys’ clothes once it had removed it?
To begin with, he would just drop them on the floor. Later, after he rested, he would go clean up the area and burn the clothes.
3) The skitter must have been fascinated by both guys when checking for a sexual response to its experiments?
Yes, both reactions would have fascinated him. He would like to have figured out the reason for the different respnses, but didn't have the means to do that.
4) When the younger guy becomes aroused and climaxes from what the skitter does to him the skitter must have been very puzzled by this reaction. Might it have tasted /taken the guys private parts into its mouth before it started to feed properly to, taste what had happened and see if there was any other reaction from the guy?
Yes, there's a good chance it would have done that. given what the boy had just witnessed, however, he would have been too terrified for any arousel to occur.
5) The younger guy must have been petrified with fear seeing the skitter eating the other guy. Would the skitter have shown the younger guy, it eating the older guys private parts to scare him even more?
It certainly would have since it was measuring fear.
6) might the skitter take the youngers guy private parts into its mouth before killing him to see if it can get him aroused again?
Yes, he might. again, the boy was past the point of being aroused.
7) Which of the two guys will provide the most food when it eats their private parts?
Probably the older one.
8) When the skitter feeds on the younger guys private parts will it take all of it in its mouth at once. Would it be able to swallow them down hole?
Yes, it would. It's jaws and throat are large enough to accomodate them.