Why does Amnesia have absolutely no idle movement?!

[KingWolf]

Oh wait, TVTropes.

You're one of them.

[Acies]

The lantern does have an idle animation - ergo the hand is moving. It's also effected by physical forces; try jumping off the map border while looking at the lantern.

As for animations in general I believe frictional games hired freelancers to do them - so that's probably why there isn't an overflow of them in game

On the topic of having items you hold move slightly.. maybe a good idea(?). Not sure what problems, if any, it would cause.

[GrAVit]

Looking upwards or downwards will sway the lantern so it seems like it's affected by gravity. The hand also moves slightly when standing still, it moves faster when running/walking.
I don't see the problem here.