I'm pretty sure Chancellor goes pretty poorly with cursing. Intuitively, the problem is that your discard pile is not generally stronger than your deck for a good part of the game, so the ability is unlikely to help you. Simulator agrees, saying that adding a Chancellor opening to Mountebank is significantly worst than just Silver/Silver (like 37-58). Of course it misplays Chancellor, but even so, it's unlikely to help much, at least as an opening. There are usually better things to open with.
How badly does it misplay? Does it, for example, discard when mountebank is still in the deck? That would certainly make a pretty massive difference.
Yeah, it does. It definitely overuses the ability, so I'm not saying that I'm getting an accurate win probability. However, the point is that you will actually not want to use the ability often, as evidenced by how bad you do if you always use it. This means that in curse decks, chancellor is actually worse than it is in non-curse decks.
Excuse my editing of the massive quote-chain if it messes up..
I agree that Chancellor is pretty useless when you want to optimise buying power. But as an opening buy, Chancellor gets your curser into play 1-2 turns quicker frequently, and has an ok (though by no means great) and cycling your curser significantly quicker after the first reshuffle. This is obviously most true with the Cantrip familiar, where I'd open chancellor/potion over silver/potion almost every game, but might also be good enough at winning the curse race to counteract the collision disadvantage with Witch/Mountebank. With IGG or Hag, though, I'd say pretty clearly chancellor is terrible in most cases (well, in IGG if you have any other terminal..)
If you don't have another terminal, might as well go Chancellor/Silver in an IGG game. Obviously Chancellor is horrible in Hag and YW games, and I'd expect it to be worse than Silver for Witch, as well: the +2 Cards drastically increases terminal collision risk, to the point where potentially better cycling isn't worth it.
As for Scout... drawing a card *after* you filter the green and rearrange is an insane buff. Tacking on +1 Card before you sift makes it more comparable to Apothecary: normally a tad weaker is my guess, but that's appropriate since $4 < $2P. It would be a strong $4 that way, obviously worth it with VP Kingdom cards and Wishing Well, and at least a decent addition to most decks. I tend to prefer a minimum-change approach, though: just make it cost $3, or look at the top 5 cards instead of the top 4; you could perhaps get away with doing both of those things. It still wouldn't be a power card, but that's okay.
Other potential buffs for the worst cards here:
-Adventurer should probably just cost $5, since what kills it is the fact it always has to compete with Gold, and the boards where Adventurer > Gold are just so rare. Alternatively, you could tack on a +Buy, so if you do build the sort of deck which can grab lots of cash with Adventurer, you're able to do better than just Province. Adventurer with +Buy is probably still a weak-ish $6, but it's no longer in the running for most overpriced card in the game.
-Transmute is just killed by the Potion cost; it would be stronger at $5, since then it's at least a reasonable Turn 1 option a la Trading Post. If you have to keep the potion, and you probably do since there are only ten Potion cards in the game, there are a number of approaches I can think of: perhaps it can give you Silver for each Curse it trashes, or maybe it should let you trash up to two cards at a time, and/or let you pass on the gain if you want to (so you can go Copper -> Nothing if you so choose). Or it could give you the new card in hand, or on top of deck. Transmuting an Estate into a Gold you get to use
right now might actually be a worthwhile strategy sometimes.
- Counting House probably wants some insurance against drawing it at the top of your deck when it's useless. Maybe add an option "+1 Action, put this card on top of your deck"? Stronger still, would be for the Counting House to gain you a copper each time you play it. Though that might actually be too strong, since it might become a strategy-in-a-box on many boards.
- At the very least, Thief should do
something for you the turn you play it. I'm okay with keeping the risk of helping your opponent with copper trashing, what I'd do actually would be to have Thief cost $5 (yes!) but to also make it a terminal silver for you in addition to the attack. That way, you're not killing your buy power on Thief turns, and the virtual cash also functions as somewhat of a fail-safe against potential lockdowns.
None of the other cards need any improvement.