If you have 2 hit points, but your turn is coming and you have a second wind (or whatever healing), you don't really have 2 hit points.
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I don't think experienced players buy that at all. D&D players are an analytical bunch.
Assuming that the character's total hit points are significantly larger than the volume of one burst of healing, and significantly larger than the amount of damage the character is likely to take in one turn, that healing can easily be expended in a calculated, stress-free fashion to maximize durability.
Are you basing your analysis on play experience, or theory?
The pacing of combat that RangeWicket describes in the OP is exactly the one I've seen again and again in 4e combats. I have quite a strong dislike of traditional D&D "victory by attrition", and one of the reasons I stopped GMing Rolemaster in favour of GMing 4e was precisely because it had robust mechanics to make combat something other than attrition. And incombat healing, as described in the OP, is one of them.
There is no doubt that players, through clever analysis of the ingame situaion, can work out how to optimise their healing. Just as, through clever analysis, they can work out how to optimise their attacks. This is part of the attraction of playing a mechanically crunchy, rules-based tactical game. But it doesn't make the game unexciting. For these players (and, frankly, if you're not one of these players, why are you wasting your time on 4e?),
it is a source of excitement.
Just like it's exciting to see impossibly many enemies, and work out that if the mage just telports the fighter here, and the fighter then attacks and marks this many foes, and the paladin goes and holds this other bottleneck, then it might just work out provided that the PC sorcerer taking up position on the roof isn't spotted by any scouts that the bad guys might have . . .
It's a dimension of tactical gameplay, and a source of excitement, that 4e reliably delivers. I would go so far as to say that it is the most striking feature of 4e combat - it's only competitor in that respect is the importance of movement and position.
You have to reach your turn (or an ally needs to help you). In by far the majority of cases I have seen, that is not a trivial stipulation.
But if you have to choose between attacking your foe or backing off and catching your breath -- or if your party healer needs to rush into the fray to keep you alive, putting himself at risk -- it's not an empty choice.
Yes to both of these. 4e has integrated incombat healing into its action economy, its movement and positioning rules, etc. I don't know if I would call the integration "elegant" (there are a lot of moving parts, and sometimes they're not imperceptibly smooth in their movement), but I think it pretty reliably produces a good gaming experience.
The problem here is that manufactured excitement feels manufactured. Organically grown excitement provides 50% more of the daily recommended levels of awesome.
In the context of a game - which is iteslf an artefact - this distinction is artificial (or, if you prefer, manufactured).
The question is - is it more exciting to know that, unless you roll 96+ op your attack roll (and therefore go open-ended), your PC will die? Or to know that, unless the player of the cleric PC can come up with some clever plan to keep your PC alive, s/he will die? I've played both games. Both can be exciting. I think 4e is more reliably exciting, because it produces the need for the hard tactical choices more often.
However, everything in an RPG is manufactored excitement. It's merely that the techniques for manufactoring it vary widely. Naturally, some of these techniques appeal to some people more than others. Which is why basing a critique on X being manufactored is a null argument. 
