The version collected by collected by John and Alan Lomax from Elihu Trusty in 1937 is in the DT, and includes the verse:
"Peter got anxious and he said, Wash my feet my hands and head"
I think that's your mystery verse 5 (Dwight's accent is little difficult for us Limeys to follow).
As for:
"Never been to heaven but I've been told Its a first class city and its features (future's?)gold"
I've always heard that as 'the streets is gold', which fits in with the version Cecil Sharp collected from schoolchildren in Oneida Institute, Clay Co., KY. They sang:
"Haint been to Heaven, but I've been told That the streets are pearl and the gates are gold"