Rather than 13/8 I would say it was alternating 9/8 (three triplet beats, 123123123) and 4/8 (2/4? same thing right? 1212) measures. I guess that's just a matter of notation, but I'm used to seeing it like that in heavy metal that will throw in a 2/4 once in a while where needed.
Yes, it could be printed that way. Every classical musician I know hates it when editors do that, though -- it's exactly the same amount of work to keep track of the beats, but the alternating time signatures eat CPU cycles because you have to make sure that every change is the one you expect.
