Scout should look at the top 6 cards of your deck, not the top 4.
Fishing village should be $4.
Adventurer should be $5.
Merchant ship should get the +buy, not Wharf (I'm glad I'm not the only one who's thought that..)
Horn of Plenty should be worth $1.
JoaT's spy effect should happen last. JoaT is too strong not because of the power of individual effects but because of the self-synergy.
Farmland should be worth 3VP.
Torturer should only discard 1 card if you choose that option and already have <5 cards in hand. Donald says the attacks are designed not to stack within a turn and the "gain a curse in hand" seems to be an attempt to do this, but Torturer still stacks like crazy.
Harvest should reveal 5 cards.
Tribute should reveal 3 cards and let you choose two.
Jester should not let you gain more than one card.
Develop should let you choose whether to put cards on the deck or not.
IMO of course!
I disagree with a lot of these:
Fishing Village at $4 is something I considered and almost put alongside Ambassador at $4. I'm not too I agree with it now. Firstly it means there are no $3 durations (meh), but also... what would really change? Not grabbing two FV's with $6, occasionally?
I don't think HoP needs $1. It's a niche card currently, but it's not so weak as to need a whole $1 boost (that's a seriously large boost, BTW, just think of the difference between Copper and Silver, or Silver and Gold). There's the neatness of it being a treasure therefore giving >=$1, but then again, we already have a treasure that can give 0 (Philosopher's Stone)
If you want to change Jack, bear in mind it's designed as a post-attack repairer. Drawing cards, then trying to get rid of the top-deckked junk you've been left with defeats the idea. It makes it weaker, yes, but defeats the idea. I considered the following I'd have tried if I were designing Jack myself:
"Look at the top card of your deck: Discard it or put it back. Then choose 2 (the choices must be different): Gain a Silver, OR Draw until you have 5 cards in hand, OR you may trash a non-treasure card from your hand."
So you get the top deck clearing (Jack's weakest effect in general... I suspect) for free, then choose two of the other three. So unless you're getting hit by lots of different attacks (discard, deck order mess-up, trashing and junking), it still fulfils the original intent, while being generally weaker in non-attack games.
Farmland at 3VP would be less interesting. You'd almost always take it over a Duchy, reducing the interesting strategic space around the card.
Torturer... it'd make the card nicer. But it would be awkward to word. And I'm not convinced it's necessary.
Harvest revealing 5 cards... actually, I quite like that! I expect it would gain you about $0.75 more and make the card reliably about $3-4 with a chance of being a bit more or less, rather than generally $3 and occasionally $2 or $4.
Tribute I agree with what others have said. Let it just compute both cards regardless of their names.
Jester... what, you can choose one to gain, but everyone else has to gain a copy of it. Far too targetted. Everyone reveals a King's Court. Result? Everyone but someone you choose gains a KC. If you want to change this, better change Noble Brigand and Thief too.
Develop I also like the idea of. Develop needs a little something to jump start it, since it's such a cute little card.