Rules issue: Where does the action card copy you play come from, and where is it discarded to? Presumably the implication is 'this Envy is a copy of that card until it leaves play; the opponent discards that card.' This faces a MASSIVE problem with politics; it really ought to make all the opponents discard the revealed card, or you can just pick on one person and... take them down with you I guess.
Envy is gained whenever you could gain a curse? Seems like a REALLY bad choice most of the time. Lose an extra 1 to 4 VP for a relatively low chance that curse might instead be a useful action card, on a board that might not even have action cards other than Envy? It seems likely to be self-defeating a lot of the time, because you play Envy, gain two curses, your opponents each reveal an Envy, and then... you're screwed. You've wasted an action to do basically nothing, or to gain two curses and play an Envy, forcing them to discard a junk card and then hoping that they might have something better? But you've junked your deck more than they have, and you can't choose to get Envies instead, and you only have a three-card hand next round, from which your opponents might then be able to discard any action cards you have by playing an Envy if they have one...
Seems REALLY bad. Really, really bad.
I like the concept of 'take worse penalties from junk that has a chance to be better later', kind of like Ruins, but this implementation just seems like something I'd almost never choose to actually use.
I'd be inclined to make it something like
Envy
0*
Action/Attack/Curse/Vice
Take a -1VP token, and each opponent must reveal and discard an action card or reveal a hand without action cards. This Envy functions as a copy of one of those cards until it leaves play.
----
-1 VP.
Still faces the possible pinning issue, though, and the 'frequently not actually being very good' issue. Also, being strictly better than Curse.
Maybe just make it buyable by itself, so that you can buy it for the attack? Or make it be given out by a specific junker action as well as takable instead of curse?
I'm not sure.