A:AnswerYes, it is brand new.
I don't know about sprint. I don't have service with them. You can buy for sprint service.
Normal one year warranty from Samsung. You can purchase additional warranty from BestBuy.
A:AnswerYes. I use an AT&T compatible simcard from straight talk and it works fine. I didn't even have to program the internet or text media stuff after I put in the simcard, it just started working like magic.