Now. My thoughts on the lore? I like it quite a bit. Though there's a few suggestions I'd make.
No Magic:
- At the moment, this aspect feels forced. A weakness for the sake of weaknesses. When reading the post I don't recall seeing any explanation as to what prevents them using magic. (Apologies if I simply missed it.) I'd suggest you either remove this all-together (I see it detracting from RP, not adding to it) or alternatively, that you elaborate on what physically makes them incapable of using magic.
- This is especially so for Blood Magic and Necromancy. As you stated, the creatures are required to feed on Genus and Lifeforce to supplement their own reduced ability to make them. Why are Strigae incapable of using those fuels for other purposes, at great risk to themselves? It would of course require more regular feeding and put them at risk of doing damage to themselves if they don't feed, or put them at elevated risk of devolving if they do.
Talons:
- To me, this strength doesn't fit well with the others. Most of the enhancements are focused on self-preservation. Ie. Minor improvements to strength and speed, regenerating wounds and difficult to fully destroy. These are all relatively defensive. Whereas Talons are offensive. I'd suggest you remove the Talons part entirely, either as a balance to removing the seemingly forced magic restriction I mentioned above, or as a way to further balance the strengths and weaknesses. The removal of these Talons would serve to remove a strength and add a weakness. (No real non-human offensive measures.)
- Alternatively, instead of removing them you could also downgrade them a lot. Instead of being able to grow long blade-like fingernails that can sometimes parry swords, perhaps they could just be permanently pointed fingernails. These would keep a very minor amount of the offence behind talons, without potentially problematic things like parrying swords. It'd also add an extra weakness, in that the these pointed fingernails would be another way of detecting them.
That's it for now. I'll re-read in a bit and see if I notice anything else.