Harris bipods are used to help stabilize any rifle by attaching onto the sling swivel stud of any rifle. Harris bipods are quick to detach and clamp and come in a variety of sizes.

It all depends on the Rifle and bipod model.

Unfortunately the creators of COD WAW do not allow players to deploy weapons with bipods in Nazi Zombies even though some weapons clearly have bipods and others even have bipod in the name

All bipods and tripods can be adjusted to some extent.So if it comes with a bipod you can adjust it.

It depends on the gun and the bi-pod.

Some minor wobble can be expected from most airsoft guns.