From #3 above, issue #2 is not present in 13.04 and is present in 13.10+. This would lead one to believe the problem is either in the SCA or in the software-center client (in one of the USC components). Issue #1 on the other hand is likely due to the multiarch packaging issue mentioned below in paragraph #3.
Unfortunately the way that the USC (generically) handles multiarch, the package in partner is a "split" package that pulls in the 32 bit application and handles the multiarch deps for 32 bit and 64 bit. I suspect this may play a role in this issue.
If you look at the packaging there is a skype:{i386, amd64} package that depends on the skype-bin:{i386} package in the partner archive.
From #3 above, issue #2 is not present in 13.04 and is present in 13.10+. This would lead one to believe the problem is either in the SCA or in the software-center client (in one of the USC components). Issue #1 on the other hand is likely due to the multiarch packaging issue mentioned below in paragraph #3.
Unfortunately the way that the USC (generically) handles multiarch, the package in partner is a "split" package that pulls in the 32 bit application and handles the multiarch deps for 32 bit and 64 bit. I suspect this may play a role in this issue.
If you look at the packaging there is a skype:{i386, amd64} package that depends on the skype-bin:{i386} package in the partner archive.