Ftf is fine on a rifle. However, if sending it has to go ups and by law if it changes ownership it must be sent to a ffl and the background check run.
I don't think this is accurate. I think if sending it, you can send in a box at that post office and sent directly to the other individual with no FFL involved.
it can go any shipping method. usps, ups or fedex as long as the person getting it is a resident of the state, no need for a ffl. after the initial purchase there is no requirement on transfer unlike a handgun