Two Apple IDs from two countries, one Mac: how to deal with MAS?

I have two Apple IDs, one associated with the US store, and another associated with the Italy store. I have iOS apps on both accounts. I used to have to switch back and forth between accounts to get them all to update, but iOS 7 seems to finally be able to update them all transparently (correct me if I'm wrong).

I also have some Mac App Store apps (including Mavericks itself, obviously), and so far all of these are associated with my Italian ID. However, I would like to purchase some new apps from the US store, because the prices are much better. I live in the US and I have an American credit card, so that should not be a problem.

However, from what I've read on this forum, the Mac App Store still gives an iOS 6-level experience with multiple Apple IDs: you have to log out and back in to perform the updates, which seems like a pain. So, if I buy the apps using my American account, I will be forever doomed to juggle accounts back and forth. I wonder if I would even be able to see OS X software updates while I am logged into the American account.

On the other hand, if I change the country of my Italian Apple ID to the US, I will use access to all of my previously purchased apps. Apparently there is a way to get the Mac apps purchased with the same Apple ID transferred to a different country store. However, I am not aware of any such workaround for iOS apps or iTMS music, so I would permanently lose the ability to update or redownload those apps.

Is my understanding correct? It seems that buying Mac apps with the US Apple ID is the lesser of two evils, but I'd be forever stuck switching accounts back and forth on OS X to make sure everything stays up to date. Is there a better solution?