... Good point. It's not quite the same as the participial phrasing as I normally think of it, though. It's almost adjectival--can be embedded into the middle of the noun phrase, and it includes a reversal of word order. I know there are a few standard uses of such phrasing ("gun-toting assassin," "card-carrying ), but it seems to have a really narrow range. I admit, it's an area of syntax I haven't looked at much.

"-n desu" is one of the few constructions I remember from Japanese, which is weird because I don't use that one as much. (My brother says that Coloradans one-up that with "what it is is that such-and-such happened.")

I'm assuming your ", so ..." ends a sentence and implies information already known to all parties? I can't remember quite what "ga" and "kedo" are for, but I use "so" that way too ...