All that you have stated is the same with possibly any fastpack out there, well maybe except for the landing gear, I guess that will depend on what 1/48 you have.
The micro missle pack on mine both are the same, no left or right side (just look at that red dot)
As for the arms, yes it just hangs on those little holes. For the gunpod, yup that red thingie kisses the ground
Probably why they always land on Gerwalk mode.