Learn English – Using the verb “fail” when we are talking about the exam in the immediate future

The expression that sounds better to me to express decision-making in this context would be:

Ah, whatever. You are free to do anything. It's up to you.

Because that way you are telling someone you want him/her to decide about something, which would be the same as: "The decision is yours". For me this is the big difference compared with the "* all yours" expressions which don't necessary imply decision making.

Usually "(*) All yours" is used to express the availability of someone or something in an informal way:

A: Can I borrow that book?
B: Sure, it's all yours.

A: I'd really need your help this afternoon if you're free.
B: I've got a meeting at 2, but after that I'm all yours.

Or to tell that something now belongs to someone:

The course requires you to pay the fee only one time and after that it is all yours.

In your last example, it seems right to use "They're all yours" (at least for me, the other options don't sound natural) because the workers could be treated "as someone wants", that could be interpreted as them losing some of their rights as humans and "taking them as objects". I've found a similar use in this book, but with girls instead of workers.

Extra (related with some previous comments on the question): "It's all in your hands" is more like "it's down to you". These expressions are used when for some reason you're the only one who could take that task at that moment. See this

frogmarch (verb)

Here is a definition quoted at Wordnik:

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

march a person against his will by any method
carry someone against his will upside down such that each limb is held by one person

Wiliam Safire of the NY Times quotes a slang dictionary from 1873 as saying,

the manner in which four or more policemen carry a drunken or turbulent man to the station-house. The victim is held face downwards, one constable being at each shoulder, while the others hold on above the knees. Often another officer beats time on the recalcitrant hero's posteriors. [emphasis added]

Here's what Merriam-Webster.com currently says:

to seize from behind roughly and forcefully propel forward

So, the meaning may have shifted somewhat to no longer require being held aloft, but it's still probably the best single-word choice.