1. No, promoted elephant and knight cannot promote further.
2. I think knight and camel have same value or the camel is stronger. The reason for knights promoting to camels is their movement, knights are (2,1) jumpers and camels (3,1) jumpers.
3. I must have been sleeping when I wrote this. I'll upload the page as soon as possible. En passant is NOT in this game. :/
4. As in shogi, you can't mate with a dropped pawn. I'll include this when I upload the page. Stalemate is draw, as in FIDE chess.
Thank you for the comment!
Hope you'll enjoy playin'!