After the second year the crusade was sitting in its starting province (64 zeal not 68 like I said before), it was already dwindling.

The inquisitor (3 stars) I sent wasn't a big succes either. After his first year he got the zeal up with the amazing amount of 1 %. woohoow.
A question about an inquisitor: How long does it take for him to go on a killing spree?

Thirdly, if I want some advanced units to join my crusade when I let it set in its home province do I need have the buildings that produce these in this province? Or just the castle? Or is it sheer luck?