These 'kludge' rules are what makes chess what it is. Take out stalemate
and the beautiful endgame studies of the past are gone. Stalemate is surely
not a win since the objective was to checkmate not to capture the king.
Change this and try this - it does not work. You are making a game with
LESS not more.
Castling is a king safety rule - that speeds up the game and makes it more
dynamic. Take it away and try it - the game is slower and not as
interesting. Shuffle chess without castling or Fischer random - it seems
people have already decided.
Eastern variants dont have the queen- Chinese chess the king is confined
to the palace - the stalemate =win seems more logical in that context ..
The double pawn move and en passant go hand in hand as well.
I have actually taught kids to play chess - and they have no problem
picking up the rules in one go. If anything, its the movement of the knight
that confuses them.
I think what is important to note is that even the smallest rule change
has significant effect. Lets call it as it is - we are making different
chess-like games. Maybe for the chess variant community this is still chess
or next chess but for everyone else - it is a different game regardless of
how chess-like it is.