Resupply crates, picked up weapons and marking planes/tanks

Ok first point. Resupply chests. they are great but a few things that maybe bugs or not. 1 I can not seem to get my Eng to resupply his ammo from the chest. It acts like I am trying to resupply the chest. 2 A picked up weapon with 5 rounds or sometimes less, can not be supplied with more then 5 rounds?? Also why when the Eng picks up a weapon can he not get more ammo?
Lastly it would be nice to mark a plane. So other planes or even players can see it on the map. That being the point a marked Tank tag should stick with it. Not the area you spotted it in.

yeah, it would be great if tank and plane tags stuck with them (for a time limit of course, but they can easily be re marked)