Is the action Ready Weapon also used to holster or sheathe a weapon?

If that isn't the case and you wanted to change weapons mid fight, aside from dropping one on the floor is there any other mechanic to allow you to put a weapon away before drawing another one?

I ask because if Ready Weapon is also the action to holster a weapon, it would be technically possible to draw an FA capable weapon, fire a narrow full burst and then holster the weapon in a single Action Phase.

You would need to be an adept with Quick Draw power (as this is the only thing that allows you to draw and use a Complex Action to attack) and the Krav Maga martial art ability to make Ready Weapon a Free Action (so you could then holster as a free action) in order to pull it off.

Aside from the potential coolness factor of being that quick on the draw, could this potentially be used in a 'hand quicker than the eye' way to give Perception check modifiers for observers to notice the attack being made? Presuming the use of an AVS modified to FA, sound suppression is also a factor, so someone surrounded by a crowd of people could potentially draw, fire and holster before anyone else acts, causing confusion and allowing them to remain unnoticed as the shooter by observers.

This possible, or just cheese? If possible, any idea on likely Perception modifiers to notice who was the shooter?

If I were to allow this, it would only be applicable when using a Quick Draw holster. It wouldn't be possible to accomplish (in my games) with a normal holster.

Actually, that begs another question. The standard Quick Draw action has a threshold of 3, which is reduced to 2 by a quick draw holster. The adept power Quick Draw already has a threshold of 2, so does a quick draw holster reduce it to 1?

I had always assumed that the adept Quick Draw was magically assisted, and therefore acted as if anything drawn was already in an accessible position (hence the lower threshold already). Given that, a quick draw holster shouldn't really make any difference to the draw.

But you're not using the power for the re-holstering. And while Krav Maga doesn't have any requirement for a quick draw holster either, it was also developed for use mainly by non adepts. Since you're already doing a trick that's impossible unless you're both a martial artist and an adept, I can see where it'd be resonable for a GM to expect you to remove any extra impediment to be able to pull it off.

No, it isn't. There are general-purpose actions to do so.