The flowers of pretty much all edible fruits are also edible.
Here in the northeast, I have the following vines growing: grapes, akebia, schisandra, maypop passionfruit, hardy kiwi, arctic kiwi, (I am thinking about trying a regular fuzzy kiwi but I cant find a female, that is hardy enough).
Arctic Kiwi and schisandra are suppose to be shade tolerant. I think that maypop passionfuit would be okay too due to the fact that you would have a longer growing season. I would look for short season/early bearing/dwarf cultivars and try out all the vines available for your climate.
Mirlitons (Sechium edule, chouchou) are completely edible. Around the world people eat the tender young vines and tendrils, the fruit, and the tubers. Young plants are grown as asparagus-like palnts. Reunion Island in particular has a cuisine based on Chouchou. See:
Yes! Akebi grows wild here (zone 7-8) all over. It grows deep in the woods, so very shade tolerant. Everyone knows their own secret spot in the woods to pick akebi, if the monkeys haven't gotten to them first.