Rules question - conspiracies and timing

Watching the latest Wednesday stream made me wonder about conspiracies and timing. 

Let's say I'm in a four player game and I play a conspiracy that requires four prestige to trigger. 

I show it to player B who declines to contribute. 

I then show it to C and D who add one prestige each. 

Two possible scenarios for my next turn:

1. I add a fourth prestige and want to resolve the conspiracy. Having seen the conspiracy, B chimes in and wants to add a prestige after mine, but before I can resolve the card. 

2. I add a fourth prestige, but choose to wait and resolve the conspiracy during a later turn. At some point, during this turn or a later one, B wants to add a prestige to my conspiracy. I want to resolve it before B's prestige is added. 

Would both scenarios come down to the active player - who would be the person with the conspiracy - choosing what happens first? 

So the only difference between the scenarios being that in 2 player B can force a resolution to keep the card from being saved for a future turn?

Same doubt! Other Players can put prestige on conspiracies at any time?

That is a good question.

Players can put prestige on a conspiracy only during the conspiracy's controller turn. Any player the conspiracy card was shown to can place prestige on it.

So, for scenario 1, I would say the active player has priority so that player could resolve the conspiracy before any other player contributes to it.

In scenario 2, however, it seems a bit more complicated. If the active player decides not to resolve the conspiracy, but B decides to chime in... I see two possible outcomes:

1- In response, active player decides to resolve the conspiracy targeting B, before B can contribute the last prestige.

2 - Active player takes no action, B contributes the prestige needed, and the conspiracy has no legal targets, thus remaining face down for the rest of the game.

This is certainly an interesting situation. What would be the correct procedure to resolve it?

Mentioned it on the Discord, but I'll put it here as well since it'll be easier to find. In a game, I would never show a Conspiracy to all the other players in the same turn. In theory, Player B has the entirety of Player A's turn to contribute. They could choose not to when first shown the card, but then after Player's C and D contribute, B could then choose to add a Prestige during that same turn, assuming A still doesn't have enough Prestige to resolve the card. This would then leave Player A with no targets.