It just becomes "If the Boon/Hex is good, this card is good and if they aren't then they aren't." Which to me is much less interesting than the printed cards.
Which of the Boons would be bad on a Smithy? Will-o-wisps do risk being drawn dead, but can be very powerful when they aren't "bonus" cards, and you can use it to help activate the self trashing.
The thing with Tragic Hero is that the +buy is really important because it lets you buy back Heroes after they're trashed. So most of the Boons will be worse than that. Flame and Sky's gift are probably broken on this though. - especially Flame, that's like a super Masquerade that turns into a Gold when you're done trashing... Sea's gift also messes it up too.
Tragic Hero- I don't think Tragic hero needs a buff, +3 cards and a buy isn't bad for 5.
It's a slight buff, but that's not what it's about. It's about being more interesting/varied. The current version seems like Margrave except it attacks you instead of your opponents.
Ah yes, I think this is the problem in your thinking. If you don't want treasures you don't buy a Tragic Hero if it's likely to trash itself! If it isn't likely to trash itself it's basically just a Library with +buy that you can Mining Village style blow up on the last turn. The fact that people are thinking that Tragic Hero is weak is a telling sign that it's actually just interesting, it's fairly situational sure, but it has a very powerful effect in the right deck.
This version of Bard is also clearly too good, Sea's gift turns it into Poacher+, Field's Gift turns it into Conclave+, Forests's gift is non-terminal Woodcutter, Wind's gift is like a double Oasis thing. These are all too good on their own, and this Bard gives you an option of 2 Boons! No single Boon makes Druid stronger than an existing $2 card by itself and this should follow the same principle.
Tormentor is probably my least favourite card in Nocturne anyway, I'd rather it just stay simpler and unobtrusive like it is now or be replaced with something completely different.