On the issue of weapons only being unlock-able in the shop, I think that may have been some kind of UI bug in the beta. When I played with my friends, they complained when they saw the “Unlocked in Shop” tag on certain guns. When I looked at them on my end, they had regular level requirements. None of us pre-ordered anything or purchased anything. When I reached the required level in the beta, I unlocked the gun that my friends indicated was “Shop Only”