Under the 'cool idea' model you're certainly right, and the Wrath of God effects don't help that sort of thing. Counterspells would be another category to consider banning. Terror maybe, but that would fit in as a general-use card.
I'm not sure whether I feel comfortable going entirely with the 'cool idea' model, since it implies to some degree that you're just out to do your cool thing and also that, to some extent, you're not allowed to defend yourself. (Terror would be an attempt at defense. Wrath of God would not.) That doesn't quite explain it though, because you could include Wall of Faith instead. If decks are *only* based on your cool idea though, it becomes a matter of who can pull their idea off first, and that's nothing more than a mana efficiency race---not a terribly exciting way to describe a format.
One thing I've noticed as we've gone along in this discussion is that nearly everything we've described are effects belonging largely to instants and sorceries. I wouldn't want to put in a no-instants rule to deal with destruction methods since I think that Flame Burst deck you designed was a great example of 10-card, but it does describe the problem somewhat. (Bane of the Living would be one example of another problem such a rule would have.)
The problem is with the lack of ability to have extensive redundancy in a 10-deck. Losing a forest isn't as big a problem if you could potentially draw one next turn. Lands I don't see it as reasonable to expect a good 10-card player to include a redundant land, but what about a mana elf? Or a Crush of Wurms?
Maybe one way to solve the problem is to allow an automatic ability along the lines of:
'At the beginning of your upkeep, tap all your lands and empty your mana pool: return one card from your graveyard to your hand.'
Allowing automatic (and expensive) graveyard recursion would allow players to potentially survive destruction tactics, turning terror into a delaying spell instead of a complete game-buster. The cost I described above doesn't prevent mana elves or Krosan Restorer from adding mana to the pool anyway, but I felt too uncomfortable about forcing the player to tap their blockers. My automatically available recursion idea probably comes with more problems than it solves, but I'm interested to hear what you guys think.