getting additional action uses

if proletariat uses duplicate, then overwhelm, can he use the overwhelm to us duplicate again? Despite it not being unlimited? Also, what if beacon were to allow proletariat to use overwhelming duplicate with bolstering team up, after he had used duplicate on his own turn already? Would that work? And finally, is it possible for legacy to use motivational charge on an allied proletariat, hitting him, and thus making a clone due to the card proletariat has that reduces damage to one and makes a clone, and then proletariat is healed by motivational charge resolving, so that proletariat effectively gets a free clone? And if beacon moves, then does bolstering team up, can she use her bolstering team up action to move again?

Yes, Overwhelm allows you to choose any action.   This would result in a total of four Proletariats on the board after those two actions.

Also, what if beacon were to allow proletariat to use overwhelming duplicate with bolstering team up, after he had used duplicate on his own turn already? Would that work?

yes, it's a new turn and this would be allowed   

And finally, is it possible for legacy to use motivational charge on an allied proletariat, hitting him, and thus making a clone due to the card proletariat has that reduces damage to one and makes a clone, and then proletariat is healed by motivational charge resolving, so that proletariat effectively gets a free clone?

You have to choose the order to work that way but yes this is possible   

And if beacon moves, then does bolstering team up, can she use her bolstering team up action to move again?

I believe Beacon would have to choose a different action

Bolstering Team-Up lets Beacon take an action.  The action chosen will follow all normal rules.

Overwhelm says to select an action, not use it.  Each Proletariat takes that action.  You are not using the selected action, Overwhelm is giving you the effect of that action for each Proletariat.

 

That is the difference.

This^^
This is what I needed to help explain why Tachyon does not get an extra attack when earning an extra sprint from Unrelenting Momentum. The sprint means she may make an active attack, but not take the action associated with the attack. Since the action to make the attack was not spent, Tachyon cannot Sprint->punch,Sprint->punch, Free Sprint->punch, (free punch), unspecified third action. I had such a hard time justifying this.

I should really start pointing to health actions and passive hazards to help explain how attacks can be separated from actions taken.

Wow. This also helps explain why a Wraith with Slip into Shadows may sprint twice on her turn, as the Slip into Shadows sprint is not an action taken. Thanks for the concise explanation!