To answer your questions, the larger the container, the better. Passis develop large root systems, so if you want to produce fruit with your edulis, I'd go with a 15-inch pot or larger. You'll want to have one plant per pot. They can get pretty darn big and bushy, and for fruit production you don't want them crowded.

I'd say once they get to be a foot tall you could move them gradually to full sun, but I'm not that experienced with edulis. Someone else might have more immediate knowledge.

You might have to tie them early on, but once they're growing vigorously they'll put out plenty of tendrils on their own. You might still have to train them, because passis grow in *every* direction once they get going.

Another question.

I have been reading about Passion flower vines growing in hanging baskets. Is this really something that can be done?

I have 2 One Flavicarpa the other just Edulis... Mine are in pots as I don't (Live in a Flat) have a garden...
I've measured My Flavicarpa before now and it's in come in at 12 feet... Perhaps it would grow more if it was in a bigger pot, but not in this Flat.....