Question about approaches to FPS? Does camera-in-the-chest work (well)?

Subtopic I know little about.

I get the general-approach (?) that locally have the disembodied arms + weapons, then you have distinct, whole characters for remote-players.

Is that still the status-quo? What about camera-in-the-chest? I see some tutorials just-move the 3rd-person camera, but unsure what kind of additional issues that might introduce. For aiming-down-sights, just move the camera to the sight and do-from there?

If I want to be able to see my legs, do vaulting, crouching, peeking, etc; what I would consider general-run-of-the-mill actions in an FPS, is the disembodied approach still best?

Also, I know about this thing called Panini Projection and that it applies to FPSs, but aside from getting it’s about preventing skew on a wider FOV mapped to a 2d-screen, does it do anything else for me?

Never really delved into making an FPS, but interested and unsure what I need here… I’ve already started digging in online but there is a TON of stuff around this topic, a lot looks copied from other content, reskinned-knowledge as it were, so errors propagate…

What’s the best approach here?