Taking damage, how to represent health and armor in Magecrawl

Since I've got some downtime tonight and don't have access to my programming computer, I figured it'd be a good time to write down my thoughts on health and armor. But before that, I must ask that you read this:

TVTropes - Critical Existance Failure

This is one of the things I'd like to not do. Nearly every roguelike has a system that boils down to this. In Crawl and Nethack, and nearly every game in between, there is no difference between 100/100hp and 1/100hp. While convenient in its simplicity, it bugs me. On the other extreme end are games that track damage to every single limb, with slow healing that while makes the game "tatical", it also makes many unplayable in my opinion.

Beyond the "one hp issue", there are other issues that need working out. Another is the randomness of combat in current Magecrawl. Armor has a chance to reduce the damage taken, and when added to the evade percentage, the player can go many rounds without taking damage and then suddenly loose half their hitpoints in a round to a "lucky" double strike.

I haven't fleshed out all the repercussions of this idea, but here's what I'm thinking. The health of the player is divided into three parts over two bars:

• Health - The lower end of the first bar. These are hitpoints that don't naturally regenerate over time. Only magical healing or long rest could heal these. They represent actual wounds, broken bones, and the such.
• Stamina - The upper end of the first bar. These are the hitpoints that regenerate outside of battle. The outside of battle part is to prevent Pillar Dancing (which beyond Elbereth is one of the cheesiest tactics in my opinion). Better armor will increase this amount (almost with some type of damage reduction and/or increased MP cost for spells). These represent ones ability to stay out of true mortal harm for some part of combat.
• Shields (for lack of a better name) - This would be the second bar, only shown when you have an affect that provides it. In most RPGs, spells like "Mage Armor" act the same as regular armor. I like the idea of it being forcing back damage due to your arcane will alone. When a spell that provides protection is active, this bar would be populated with a set of temporary hitpoints that take (some? all?) of the damage before stamina/health is taken from. It's length would be based upon spell proficiency, intelligence/willpower. I like the idea of it sapping from your mp during and after battle to recharge itself, giving it different flavor than stamina. I'm not sure how to get around Pillar Dancing if I do that however, unless it only does that when you don't move.

Beyond this, there has to be some penalty to taking some damage, beyond chance of death. I like the idea of stamina damage either slowing down your CT (longer time before turns), increasing MP cost of spells, or both. Health damage should be more crippling, such as slower movement, penalty to MP regeneration, and such.

I'm trying to balance this with keeping the game fun. I'm hoping in this iteration to get some implementation of this system in and see how it plays. Any thoughts?