Well, if I should look at this as a test, I sored good. Almost only hit the top scores.
Interesting:
Which magic path is the least useful for a Pretender to take in general, under all circumstances, on average?
I don't think blood should be that high, because of the "on average" part.
Sure, you never need blood, if you are not going to do bloody thinks. However, if you are going to do into blood, thins skill imediately becomes top importance unless you want to spend hundrets of blood slaves into empowering one of your national casters.
I've choosen fire, because fire is what you either won't invest much into anyway, or what your national caster will be able to handle okay, allready.
In 7 out of 8 cases, fire will still be more useful for the pretender, but in the 8th case, blood will be more useful, ten times as strong.