Anyone with the game yet know whats up with my characters arm holding his belt when my weapon is holstered. gets annoying in 3rd person mode.

Roleplay that your character has pants that are a few sizes too big, and he's constantly trying to keep them up.

It honestly looks like it lol. Like his arm is in an invisible sling as if it's broken.

Limbs can be crippled.. check and see if you need to heal your arm.

How do I check that. My vitals are all 100%, I've been to the doctor and requested every heal. Still has a broken arm look even when I sprint.

Are you playing on PC, PS4 or XB1?

Target the actual limb in your vats status screen.