The thing about Duration Attacks wasn't that the rules are unclear about how they should work, just that it can be confusing for some and difficult to track, so fan card designers should be careful about it. Donald tested and decided it was worth any confusion. Cool.
Price gap arguments were stupid.
I don't think any of those changes actually required removing past rules. Adding new Curse-type cards would. Suppose we have:
Cuss
Cost: $0
Type: Action-Curse
+1 Buy
Worth -2VP
OK, first you have to decide what it means when cards say "Curse" vs. "Curse card". The easiest solution is to say that they all refer to the card type rather than the specific card, otherwise all the junkers arbitrarily change in value and balance relative to each other. If the meaning of the terms is kept consistent, at least all the Cursing cards will remain in balance compared to each other. This is a fine change.
Now you have to rewrite what it means for setup. You have to put a specific number of Curses in the Supply depending on the number of players. But what about Cusses? Do they count as Curses for this, or is that setup rule specifically referring to the specific Curse card? If the latter, how does Cuss even enter this game? If Cuss is in this game, do you put in fewer Curses to compensate? These questions are not trivial to answer.
Now when I play a Witch, do you get a Curse or a Cuss? From the new ruling, either should work, but if both are available, who chooses which type you get? Other cards specify for similar circumstances, but none of the existing attacks do.
And of course, it also really throws off the balance of a big class of cards.
A fan could certainly go for it anyway, but this is a lot more problematic than Duration-Attack or $1 card.
