During the beta you could switch specialist/weapons/gadgets but not the accessories of the weapons from the respawn menu, it was only from the ground by pressing "T" with this cross menu. I guess at the final state of the game we'll be able to customize our weapons directly from the respawn menu and save the settings
Again during the beta you could drop land vehicles/bonus: ranger, 4x4, tank but not choppers. Air vehicles were only available to use from the respawn menu by clicking on the car icon (yeah very logic)