Re: end of pickup wiring - hot or ground??
welcome
i am not sure i understand your question becuase you add in items that confuse the issue
in essence, either the start or the end of the coil can be hot as long as the opposite end is ground ... the difference will be manifest in the electrical polarity of the signal, which really only has influence when combining more than one pickup ... the electrical polarity of one pickup acting alone is inconsequential
as for a shield, the pickup needs its own 'ground' wire separate from the start and stop wires for this purpose
i hope this helps somewhat
perhaps someone can come along to answer about efnder pickups - i do not know this answer
t4d