and you know this how? i haven't read alll rulebooks, but i have read most (though the german ones have been missing things before).
The burden of proof is on you. This dichotomy between primary and secondary types exists only in your mind. If you want to show that this distinction exists, show me where the rules delineate them. Let me save you time: the rules make no such distinction.
so, to summarize, you don't have any proof for your claim that all the smaller stuff (attack, reaction, etc) are also types, you only think so because these things are printed on the same spot where other things that we call types are also printed. is that correct?
that doesn't seem convincing to me at all. the real question is of course not whether you're right, but whether or not most people would instinctively get to the same conclusion. if someone asked me, I'd say that it's not clear, and If i had to guess I'd say only the main 3 (action, victory, treasure) are types, because they include almost all cards and don't overlap. i apparently have a strange way of thinking, so it might be just me, but I really wouldn't take it for granted.
I think it is clear enough. You can name Curse, Reaction, Price, Attack, Duration, whatever -- if at least one card among the four has that type.
I'm assuming you can choose any card to put into your hand, not just the ones the player to your left indicates. Otherwise your opponent just shows you which cards are Victory cards and you have to draw one. The text isn't clear, but I think that's the common-sense interpretation.
Yes, this is how it should work. I will change wording based on yours.
The card has accountability issues. Yeah, you're probably going to see the 2 cards you put back eventually, but ideally you find out what they all are while the Action is resolving. At first I thought this couldn't be fixed, but one solution is to just discard all the cards you don't draw. That way you can confirm that the player to your left was honest about what was what. This also eliminates issues with ordering the 2 cards you put back on your deck. "Did my opponent reorder those cards? Hmm, better shuffle them up a bit." If they're discarded, you don't need to worry about this.
I would also simplify the card by just caring about types, not cost. The concept still comes across, but there's a bit less decision-making. I think my ideal version of this card would be:
Fireworks: Action, $2 or $3
+1 Action. The player to your left looks at the top 4 cards of your deck. He chooses a type that at least one of them has and indicates to you all of the cards that have that type. Put one of the cards into your hand and discard the rest.
The original version tries to copy exactly the things that you do in Hanabi: Pointing at all cards with the same number or colour (the only difference is that in Hanabi you can say "you don't have any yellow cards"), then playing or discarding cards about which you have more or less information.
I intended the card to be a self-combo (and combo with other top-of-deck mocking cards) so that you may collect more information. Even if you know that the top 2 cards are
not [insert cost/ type], it may be useful. E.g. you know that the top 2 cards aren't Treasures. You play the next Fireworks and get to know that the 2nd and 3rd card costs $0. So you will likely be discarding the 2nd card.
With your version, you can't collect information about your future cards.
Another difference of my card to Hanabi is not rules-wise but in real gameplay: The opponent will rather give you the worst hint; in Hanabi you'll get the most useful one as the game is co-op.
This makes the card bad and your version even worse because he won't give you a hint about a good card. Getting a good card becomes a "1 out of 3" gamble in most cases. It is more satisfying when you are able to discard that one card that you know it's bad - while your version discards everything.
I agree with you that caring about types is enough. It makes the card better because it leaves less choice for the opponent. Maybe it makes your version good enough.
Now I would do it like this:
Fireworks (Action) $3
+1 Action
The player to your left looks at the top 4 cards of your deck without changing their order.
He chooses a type that at least one of them has and indicates to you all of the cards that have that type.
Put one of the 4 cards into your hand and discard one.
I see the accountability issue, but, well, it's not a card for everyone, you need a honest playing group for it. If a player makes an untrue statement, it won't be by an oversight. So it's no problem in my opinion. If people don't trust their fellow players, they can use LastFootnote's version.