Zack's clone, your exactly the kind of reply I wanted on this post. You showed other theories which is exactly what i wanted. I think your Zack idea is perfectly possible. I heard someone say once that Cloud loved Tifa and Zack loved Aries, and it was only Zack making Cloud so close to Aeris. Also, I didn't label this post spoilers, because Aeris death is so commonplace on the internet now, its not really a surprise to new players.

Its a shame really.
As for Breine, I'd love to see more post like this too. My favourite thing about all great games, especially FFVII is the plot which has some very complex holes to think about. I play games for the plot rather than the gameplay thanks to this game

--Cal