When this reveals your $5 or a silver, you are put in an awkward spot. I don't understand why you can discard the top card of your deck last. If you move the discard before the reveal from your hand, like Scrying Pool, you can choose to get rid of the $5 to help your trashing.
The discard is so that you can past over your non-trashed card. If its your first Silver or a $5, you most likely won't trash nor discard it. Is mostly to have some consolation if you reveal a bad card but have no copy to reveal in order to trash it (likely, your first Curse, but also possibly an Estate if you are unlucky).
This rewards a 5/2 opening too much, I think. A player can trash 2 estates and a copper as well (a 4/2 opening). This is faster than Chapel and you don't need to even spend an action and the card added to your deck isn't as dead.
Actually, if you trash 3 estates, you gain a Copper-equivalent, and if you trash 2 estates and a Copper, you only trashed two estates, so its fast trashing for opening, but I don't think its super-incredible (at least, not a lot better than chapel, and it gets bad much faster, as it consumes your buy and your turn more often, while Chapel can still trash a missed Estate or Copper or Curse in the mid-game, while this is all-or-nothing).
I think this can work better after the opening. If you open with a drawer, I think trashing an extended hand is really useful, and you already have a good action and possibly a Silver to compensate. Moreover, if this collides with the Silver, you can just play it alone and trash everything else, so I think as T3 or T4 buy is less swingy than Chapel. Maybe it is overpowered as opening buy, but its hard to tell.
Finally, I think it can also work as a "clean this engine before getting green", similar to Forge, but is tricky to avoid trashing your good cards because you need to play them for that. But, for its cheap cost and the on-buy effect, it may be better on that task than forge if you have spare buys, because it saves a lot of tempo.
I'll comment when I finished testing them (currently I've only tested solo play, which I'm not good at), but I appreciate the early comments.
