one he has turned to a vampire
CRAP! That escalated quickly...
Ok, I see you have come out with a very personal game setting.
I can see a vampire as a honorable character. The evil cloak too, is something he may have started to wear reclutantly, or as an extreme measure. If not, it's a clear, steering decision towards the New Wave of Knightly Badness.
So, if I may suggest, why doesn't he try to become one of the gods? Maybe he must avenge his former god by executing his Slayer.
Or he can be contacted by a fourth, neutral godly Essence, who's in charge of maintaining the Balance.
Just my two cents.
About the questions, the parts really out of (new) character are the "Within the Law" and "Protect another". The others, IMHO, are still valid, and could contribute to make a well rounded anti hero.
BUT: which version of the Knight is this? I have one, WITHOUT the last two questions. Could youu tell me where to find the new version? Or is it YOUR take?
Thanks!