this is me thinking out loud on my eventual optimal rack setup (a little scatter brained):
http://www.bikeforums.net/showthread...=#post11010422
if you look at the photos from my post a few above yours, you will see crossrack doesn't interfere much with fold. sometimes it is a little more annoying to stuff into the trunk of small car with crossrack protruding, but not that much more.
i emailed peter to see about welding something like the dahon luggage socket on the front head tube, he said it wasn't a possibility but would think of other ideas.
as for being able to strap random objects to a vertical rack, the crossrack bag is huge, most likely could fit random object inside or buy a bigger single pannier and stuff inside that.
when purchasing the bike, we tried fitting the bike friday rear rack, but the seat post seemed too thick to fit between the stays when folded. still brainstorming a solution to that.