However, the idea actually doesn't fit in.
I will agree with that...
Also RuneQuest is a good example of a game with the paradigm you express.
In general you are definitely in house rules territory... No reason you cant adjust to your taste but I think by
forcing hp to be wounds you are losing a lot.
1) You lose D&Ds method for measuring fatigue. (RuneQuests fatigue was very cumbersome as a separate mechanic from hit points).
2) The concept of luck that heros have more of and as a fantastical quality which can "run out" is very much chucked out the window.
3) Hit points measuring mental effects are seen all over in the game ... Morale loss being an implication of fear numerous powers have damage because they affect the mind not necessarily damage the brain... Note intimidation normally only drives somebody from the field if they are bloodied... this makes even more sense if hit points at least partially measure purely fear/morale.
4) The plausibility of
fast recovery between battles,
second wind and
inspirational healing (by poets priests and politicians) and numerous
battlefield recovery abilities in 4e, (like the fighters regenerative abilities),take a seriously different flavor... in general they are not intended to be so magical as wounds stitching would be.
It seems to me that many of the changes that were implemented in 4e actually represent the designers embracing and expounding upon the abstraction of hit points described all the way back in edition one but only ever partially implemented
Some of the language of 4e feels legacy to me... and it creates a certain disconnect, perhaps that is what you are reacting to.(damage healing and bloodied for instance) bloodied can be sweaty, winded, shaken and uncertain.... the barbarian and tough guy heros like "bloodied" but my skilled hero prefers "winded" and my halfling rogue definitely prefers "shaken" ... he constantly questions his reasoning for being in a fight and most of his hit point loss is described with him freaking or lucking out.
I personally think something like the remove affliction ritual is closer to "True Healing" . Long term effects should require long term style solutions. A part of my game worlds story is that true healing has almost been lost from the world or atleast those with the gifts for it so I am planning to have access to certain rituals limited by extra feats - but since a feat is a big cost having it reduce the components required or accelerate the rituals in question seems a reasonable recompense. Resurrection is definitely requiring a feat.
I am considering adding a player opt in form of taking a wound for cinematic play and a non optional one for the new game I am starting which has a much darker setting...
For me adding a wounding mechanics is the way to go. It keeps a close connect to the core game. Your death blow is an example of something feeling almost like a wounding mechanic. One effect usually associated with a wound is reduced recovery of healing surges (your body is fatigued more easily and is more likely to stay that way in spite of heroic implications). Impaired performance during the heat of battle is actually not that much a feature of real wounds... they normally knock somebody under after the fact when you feel somewhat safe ... ie no I am not talking about a Death spiral.(both doctors and military studies seem to agree that isnt a real thing - weird huh.)
Anyway just thought Id mention some ideas and reasons