Honestly, I've just finished triple checking that you're FTM.
I know nothing of the way you dress or walk or act in normal situations, but using the video as my only evidence I'd say you were a genetic male. However, again using the video as my only evidence, I'd say you were in the 12-16 year old age group. I don't know if you are or not... but thats my honest guess based on your appearance and voice in the video. I'd imagine that you're probably significantly older then my guess since you mentioned that "customers mistake me for a guy".
Anyways, you wanted an honest answer, so there it is.
Oh, one last thing, I know this is somewhat off topic but in the video your chest is not visible. I'm not sure if you have anything going on down there that would change my assessment if I had been able to see the area. So, again, my guess is based solely on this one video and what was presented in it.