In other words, I need the game to allow the possibility of character death in just about any encounter.
I definitely do not need a game where you first play merely to save your resources and then give you an easy way out of having to play the end-game, where you might actually run out.
The current design of the game is a resource management game (actually, it always was). You want this to not be the case. Also the current design asks that you have a mix of easy, standard, and difficult encounters. You don't want this either.
How about the following rules:
1. Everyone gets 2 healing surges at heroic, 3 at paragon, 4 at epic level. This is not modified by constitution, and feats that add to this value are out of the game.
2. At the end of a short rest, you regain all hit points and healing surges.
3. All daily powers become encounter powers.
This will remove the resource management aspect of the game, and you can make every encounter a difficult encounter. Since everyone will only have 2 healing surges to trigger, they will not resort to multi-classing for extra ways to trigger healing surges. If someone is in a bad spot and getting hit a lot, they will run out of healing surges to trigger quickly, and run the risk of death.
If you still want to keep some resource management aspect, you could scratch rule 3 and leave the daily powers as daily.