For the first one -- everyone passes to the left? It doesn't seem like a particularly good attack because it could very well end up hurting you (if the person on your right ends up passing you a copper). Could be fun for the swinginess of it.
The Curse-->Estates card is very situational. First of all, it would be useless in a kingdom without cursing. Second, it would only really be useful if you can build up a huge hand and draw up all your curses. Otherwise, your deck needs to be completely swamped with Curses. Finally, the benefit of converting curses to estates actually isn't that huge -- your deck is still really clogged. I don't think the benefit is worth using up a terminal action with no other real benefit.
Your favourite card that costs 6p -- why pick 5 players? Why not just target all other players, like every other attack card? Not a fan of this because it is breaking other card rules. The KC/TR thing aside, saying that Moat only blocks one curse is actively contradicting the text on the card itself. In any case, the rules of Dominion allow you to reveal the same reaction more than once. Usually, this is just redundant. In this case, you could reveal the same Moat twice to block both curses. The rules allow for that! Finally, for such an expensive card, it just doesn't seem that good because it doesn't benefit you at all. That's the reason why Saboteur isn't usually a good card. Sea Hag gets away with it because you can pick it up in turn 1/2, but this card requires significant investment.
Not sure what to say about the Bonus Village. The "once per turn" restriction hurts it a lot, and that price puts it up against Platinums and Colonies...
Takes on your "Cancel" card have come up a lot. As described, it is in fact still a Reaction card -- you are reacting to another player playing an action. A card like this will never appear in an official Dominon expansion as it is very political -- you use it to target one specific player. All the cards in Dominion are designed to avoid politics. They either target all other players or don't give you a choice in the matter (e.g. specifying the player to your left). However, if this kind of thing is what you are your fellow players likes, it's a fine card to have. I don't mind some politics in my games, now and again.