You have neglected to post the caster's Hit Dice, which greatly affects my ability to tell whether bloodletting is viable.

Now, I think it's not quite powerful enough. The Death Master from Dragon Compendium had the option of using blood as a material component, and when he did, it took the place of the somatic component of his spells. Your spell list is small enough that I think you could get away with doing the same. This would allow the blood mage to wear armor and provide a good reason for doing so (rather than "the somatic components for this guy's spells, when most of them come from the wizard spell list, are relatively simple, so he can cast in light armor" Yes, that makes sense)

The Blood Telepathy and Scent abilities are both very flavorful to the point of being delicious. In fact, this is probably the most flavorful class I've reviewed in a while, so I really want to see it turn out well. Okay, let's see...

I agree with Wayfare, that replacing the Bloodletting with Con-based casting would make for an interesting (and very, very SAD) caster. Give him a d8 hit dice, light armor proficiency, and 3/4 BAB and he can even do tertiary melee too. Maybe give him some kind of benefit for drawing blood from someone (like using it to auto-Maximize a Summon spell. That actually sounds so much more awesome than it did in my head.)