Can Passiflora x decaisneana self pollinate?
If not, will it pollinate with Passiflora edulis flavicarpa or Passiflora incarnata pollen?
I don't believe it can self, although bud pollination is always a possibility. Looking in my books, I don't see incarnata or edulis listed as species that can pollinate it, but it will produce fruit with pollen from alata and quadrangularis (which it is a hybrid of) as well as caerulea. The ones you mention might be possibilities, but they're not listed.