It is an interesting mechanic, although seating might be a bit too important. You don't want to sit next to the Engine player.
Instead of making it a "Hot Potato", you could just make kind of an Auction (going in turn order):
each other player can gain this from you
On the Treasure worth problem, you could just let them discard any card. Cards on the starting hand of the turn are very valuable.
Each other player may discard as may cards from his hand as you have Actions in play. If he does, pass this to him.
Alternatively, you could go with "Treasure cards" (as they were worth $1 each, like for Plaza).
It originally said 'not including this' instead of 'not including defectors', but I thought that might be overpowered. Still could be very powerful on boards where it's easy to play several actions every turn.
This leads to a problem that if you don't play other Actions than Defector, it is impossible for them to gain it. So this would open up a mono strategy. On the other hand, you need other Actions to make (especially +Buys) to make them effective.