Well it stream webpages ( can i browse the web using safari on my TV for instance ) No, it won't do this
If i have the iPad in 1 bedroom, will it stream a 720p video on my 3rd bedroom? ( safe floor, no doors, but will be between 2 walls ) If the iPad and Apple TV are on the same WiFi connection, then yes.
Also, do i have to import ALL my movies that are in my movie folder INTO iTunes? i currently download stuff from all parts of the web and they play on my iMac, Quicktime, VLC player fine...If i understand correctly, each movie has to be encoded ( which takes a bit of time ) into iTunes...Is this correct? or no? If its on iTunes, its on your Apple TV