^^^thanks for the worldly advise, why didnt i think of that? maybe because these people were on the move and i don't know any other way to recompose the shot using ai servo!
You probably know this as you have plenty of experience in photography, but I use BBF + servo with my 7D + 200L to achieve the recomposing. Of course for people walking towards or away from you it's almost impossible as you stated also. It sometimes helps a little to have different focus point based on camera body orientation, but of course that cannot be used all the time.
I think those are good pics for street photography. Well captured!