I tried to print page 2 and 10 of an pdf to one paper(duplex) - looks like this is not possible with Skim.
I installed then Adobe Reader 11.0.17 - with this i was able to print selected pages of an PDF.
Please make this working in Skim. Preferable with an input field where you can write for example something like: 5, 7, 10, 2, 22-25
The page selection in the print panel is a standard feature provided by the system. Therefore it's Apple's reesponsibility to provide this, and you should request it there.
BTW., this is most definitely not a bug. This is a feature request.
It is a bug, because the normal way to do this at Mac is to activate the page overview and selecting the pages (holding command key) you want to print - but this is not working with Skim, too.
Not even sure what you mean. Somthing like that is certainly not standard. And again, if it was standard, it would work, because the printing is handled by the system, and is standard.