For Pentacle, the wording is unclear and doesn't work. Do you mean that you gain a Curse, and the gained curse goes on your deck? Because simply "put a Curse on top of your deck" doesn't say where that Curse comes from. Check out
Sea Hag and borrow from that: "When you gain this, gain a Curse card, putting it on top of your deck."
Coven needs to also have the "Reaction" type, and the wording doesn't work. It says "when you would gain a Curse", but then it tells you to return the Curse to the supply. Because it's "when you would gain" instead of "when you gain", you never actually gain the Curse, so you have nothing to return. You can simply say "when you would gain a Curse, you may discard this from your hand. If you do, draw a card instead." See
Trader.
Voodoo Doll is similar to Pentacle, it needs to instruct you to gain the card, putting it in your hand. And the reaction should have an "if you do". And I don't think the reaction works within the rules the way you want it to. If you play
Apprentice, trash Province, but use Voodoo Doll to trash itself instead of the Province, then Apprentice will not draw you any cards, because the "it" that it refers to is the card that it trashed, and there was no card it trashed in this case. See the Blue Dog Ironworks/Trader ruling.
Candle Ritual is an interesting
Caravan variant, but it's close to being strictly worse than Caravan, just like how Caravan is a weaker
Laboratory because a card now is worth more than a card next turn. So this might need to cost
.
The wording on Charm isn't clear, like when exactly does each other player draw a card. I assume you mean for it to also only happen once per turn, when you gain the Silver, but that's not completely clear. Maybe it could just have an "if you do", or combine them into one sentence.