Wand of Cure Light Wounds between combats?Casting all of your daily spells at 19th level requires inflicting more than 300 hp of damage on yourself. I am curious about how you expect that to work.
I thought of making the Fast Healing scale with level, but that just becomes stupid good at any level (let's say, for example, that I'm getting Fast Healing scaling at half my level... By the time I can cast second-level spells, I'm at Fast Healing 2, so I gain 2 HP for casting a spell worth 2 HP, and so on). If somebody finds a way to specifically mitigate this effect at some cost (such as the Troll Blooded feat), more power to them; I feel it's a drawback that should not have an easy, commonsense fix, and if that means it requires some concentration or even a mild feat tax, then all the better. They get an insane amount of mileage for it in the long run, so why not suffer for it? Such drawbacks are, after all, intended to mitigate reckless use of abilities; if Barbarian levels are tacked onto a race immune to fatigue, or the Venerable modifier is tacked onto a Dragonwrought Kobold Sorcerer, it reeks of cheese and defeats the point of it ever being there, so if the drawback of this class is something that can easily be mitigated by something every player has ready access to (like a race or template, or innate class feature at early levels), then it's pointless. I mean, there's a reason Barbarians get Tireless Rage at 17, in my opinion.My thought is that any optimizer worth his salt will find some way to get fast healing at a low level in order to support the hp damage involved in spellcasting. Perhaps you might as well grant fast healing 1 at some point to avoid making it a feat/level tax.
My spiel is mainly that, if I'm going to create an innate feature that mitigates the drawbacks of Bloodletting, that feature itself has to have a drawback. You know my policy here: no free lunches.
How about this:
Arcane Healing (Su): A Blood Mage develops the power to turn their arcane energy inward, channeling it through their blood to induce healing in the body. As a full-round action, a Blood Mage can spend an uncast spell to heal damage equal to the level of the spell expended.
This allows a Blood Mage to mitigate the cost of Bloodletting--but in a way that is inefficient both in action economy and in spellcasting usage. In order to incur no net damage from a day's worth of spellcasting, they have to spend a number of spell levels in healing equal to those they cast, as well as a sizable number of full-round actions (which, by the by, makes this totally useless for in-combat mitigation).
This is a good time for everyone else to chip in, because I'm bouncing ideas at you at this point.
How do you suggest I do that?The trouble with allowing hp damage to replace gp and xp costs is that it's a viable trade only if the spell in question is a combat-related spell with a limited duration, so that the hp cost is meaningful and the benefit is limited in scope. You've done a good job of that with this list, but it's rather easy to get foreign spells added to a spell list (I can think of at least five). I would recommend adding text that forbids the use of any other feats, features, or items to increase the blood mage spell list in any way.
I'm not sure being able to apply Arcane Disciple or a Bloodline feat to Blood Mage breaks anything to Hell... But I might be sure of that only because I'm not intimately familiar with the Domain lists and the Bloodline feats, and the EXP/GP-heavy spells you can cast from those lists (I have never played out a divine caster, and still have to look up domain spell lists from time to time when I write characters for campaigns). If you can give me an example of what to look for, specifically, that would be great, but even just help on the wording would be nice (as I don't know how to go about excluding other spells from the spell list; I mean, really, it has no precedent with the Beguiler, Bard, Wizard, or anything else that I know of, and it's kinda hard to write something that DOESN'T have a workaround here, where everything's RAW only if the cheese isn't scraped off it, after which the jump is quickly made to RAI).