question on FPS rig

hi unreal community, this is my first post so go easy on me.

Using blender i have an entire body mesh and rig, what iam wondering:

For and FPS, do i use the arms of the entire body rig to animate say an action just for the arms e.g reload. or since the animations on the arms are interchangeable, use two rigs on the one mesh( if possible) using just the arm mesh for the reload and leaving the rest of the body for walk/ crouch etc. iam quite confused on this topic as i have not done any animation before and just starting.

all tutorials i watch they just have the arms and no body when animating, but i want the whole body, do they fuse the arm mesh later with the body mesh or is the body mesh just left out because u cant see your own body in an FPS camera.( i want body visible)

simplified: with my entire body rig, can i make different reload animations for different objects (guns etc.) or do i have to separate the arms from the body mesh in some way, animate, and rejoin the meshes, i really dont know
there is probably a simple explanation for this, sorry if i came off stupid. thanks very much and please help!!!