hey there !
for the camera, just change its properties using the camera manager , like change the focal lenght to the value you want when you change the weapon.
the best method would be to use the collision system to prevent the weapon from clipping inyour scene.
or here is an idea :
render your weapon and animation outside of your scene (might be tricky to get same lightning/shadows) with same camera settings, and render this to a render target, and composite it on top.
You are talking about camera switching which is easy in Unreal.
What I did is I have a TPS Camera and one attached to every weapon where I set it so it covers the aim down sight.
And I switch between them when I need with
“Set View Target with Blend”
he is not talking about camera switching.
he wants to render the weapon model using camera A and the scene with camera B and combine both images to one render target.