... using a scale of 1 hit point represents a wound that takes 1 day to "heal" before it does not affect the character. [A single 7 hp wound would take 7 days to "heal"/not affect the character].
You make it sound horrid!No, just no. Track this 7 day wound, that 3 day wound and another 1 day wound. No thank you very much.
Not if you have abilities that can cancel a critical hit. Alternatively, you might start the combat with "hero" points that can be used among other things to cancel criticals and "gain" combat points during a combat by successfully performing special actions that can likewise be used to cancel criticals. Armor (used by those who are going to be criticalled most often) may give a percentage chance to cancel criticals as well as provide DR. A divine blessing may also cancel a critical etc. There are many ways to moderate the frequency of criticals.And the vitality/wound thing is just the same as the others, plus the chance of a lucky crit in the first round of combat is just plain devastating.
HTW said:While it is certainly not for everyone, having 5 or small boxes on your character sheet with a number in it is not that difficult (relatively speaking). Once a day (at the start of the day) you reduce the number in each box by one. It really is not that hard for players fluent with the current and previous editions.
I would be perfectly happy if hit points restored after a short rest. I know that this would annoy the crap out of a lot of people, but, honestly, this is the best solution for me.
Remove in combat healing entirely though. But, if you survive the current combat, your hit points restore to max.
So, you want D&D Gamma World.
Good choice!
To be honest, I never played Gamma World. OTOH, my latish 3e games worked pretty much exactly like this - healing wands meant that you were fully healed after every fight. It worked so well, and kept the pacing so high, that I would love to see it be the baseline.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.