First, great job on the skope. That's a great use of pieces.
Second, all of the creators of the pieces you've used have already given their permission. You can find a list here:
http://frworld.wikispaces.com/Nifskope+Permission+ListThere is also a thread here at FR that mentions a couple more creators that members have asked about.
Third, you are correct about the skin. The community generally doesn't have a problem previewing skopes with a kitbashed skin (as long as it's mentioned) as it helps to showcase the skope better and not everyone has the tools, skills, or inclination to skin. That being said, there is a thread that was started where skinners have chimed in on whether or not they give permission for their skins to be kitbashed:
http://freedomreborn.net/forums/index.php?topic=56760.0The big thing, which you've already done, is giving credit to the original creators. Providing a Read Me file in your skope that contains a list like you've already done is the way to go. If you get permission from the skinners, as well, you would just add credits to Read Me for them.
So, in closing; excellent job on the skope, welcome to the fraternity of skopers, and don't hesitate to ask if you have any questions. I look forward to seeing your future creations.
