I'm not going to get involved in discussing the power level of the class. I do enjoy the mechanics of the spellcasting, and I think the power level can easily be tweaked through spell slots/castable spells per day.
What I dislike (and others have said as well) is the complete lack of flavor, and the whole blood magic concept.
1) Blood Magic sounds very vampiric/bloatmage in flavor, when its really just a watered down sorcerer bloodline. The base flavor is off/terrible.
2) The all day fatigued penalty for using all of your blood magic uses is terrible. It basically means no one will use all of their uses of the ability (unless they are 100% sure its the last encounter of the day), and it might as well read that you have 1 less use than you currently do. Just get rid of that, or make it fatigued for a round or two or something.
3) The +1 CL/+1 DC is much more powerful than most sorcerer bloodlines you'd use ... except maybe some of the arcane bloodlines metamagic manipulation (ironically enough).
I'd totally revise the system - give them (as others have said) the bloodline without the skills/feats/spells - just the base bloodline ability. If you want to keep the +1 CL/+1 DC thing, just make it an entirely separate ability, and reflavor it.
Scribe Scroll bonus feat + wizard bonus feats -> very lackluster
The capstone is lackluster and has no flavor
As is its a cool casting mechanic, and I like it, but there's no reason not to prc out of the class asap.