I like #3. Can't help it. It's the chemist/physicist in me that takes the view that even an electron as a subject that doesn't even know that it's being observed still has a reaction to being observed....or something like that....
I suppose it's not purist street photography, but I like some engagement with the subject, even if it's very subtle, and especially if they are pretneding that they haven't noticed you noticing them.
I too, look forward to seeing more of your photos! Street photography rocks.