Comments/Ratings for a Single Item

I'm about to start on a zrf for this game and have a few questions.   

Are the only circumstances in which a piece promotes to the upper level
(a) when it captures an enemy piece, (b) checks the enemy King, or (c) in
the case of a Pawn, promotes on the far row?  Is promotion in such
circumstances mandatory or optional?  Also, does the Squire move to the
upper level when it promotes to a Knight?  With regard to promotion by
checking, does this happen only when a piece attacks the enemy King
directly after moving, or does it also happen when a move uncovers check
by another piece or pieces?  If it happens in the latter case, which piece
promotes?

If the first rank on the upper level is full, will a promoted piece then
be placed in the second rank?

Does 'bare King' mean that all friendly pieces have been captured on both
boards, or that the King is bare only on the bottom board?  Also, are
there any other win conditions?

Finally, are there any rules from Super Advanced Chess or Advanced Chess
that apply to Excelsior which have not been stated on this page?  In
particular, I'm assuming that the Pawns are standard FIDE Pawns (without
en passant) and not Pawns from Advanced Chess.

Thanks, Dan Troyka