To be absolutely technical, you capitalize "god" when used as a proper name, but you don't when it is used with an article. It should be: "a god." Also, the pawn promotion might be made clearer: 1) Can you promote to any piece of your own on the board? Or any piece of anyone's on the board? 2) If a player had a piece on the board, but it has been removed from play by capture or otherwise, can you promote to it? 3) Can you promote to special units? 4) When you promote to an opponent's piece that is represented by a normal chess piece, do you still get that player's special ability, or do you treat it as the normal piece? I believe I know the answer to each question, but it doesn't hurt to specify, just in case there is an easily confused player or a player who likes to find loopholes.

It is for any piece from any player that was on the board at the start of the game. I.e. if there was a warrior at the start of the game, but it was captured, you could promote to it. As for special rules for a piece it all depends on how the other players power is worded. If you promoted to an elephant it would keep all of the abilities as those are included in its description. However, if you promoted to a italian bishop, there would be no difference between its abilities and a regular bishop as the bishops abilities come from the countries power not the description of the actual bishop.

should be reworded to say destroy, instead of capture