If it doesn't require a feruchemist to make an SI would using them make a super SI?! I think that a feruchemist is needed, as it seems they have some feruchemy attributes.
I personally believe that the sacrifice does need to meet certain character qualities to be used as a sacrifice, but I don't think they have to be a feruchemist (or a mistborn/misting). Here's my main line of reasoning against that particular theory.
So say that it works as you say, and they get their feruchemy attributes from a feruchemist. It would follow, then, that they receive their allomancy attributes from allomancers, right? So say you capture 10 mistings (or mistborn) and a feruchemist for your sacrifices. This should theoretically give you all of the power that the standard mistborn has, plus feruchemial ability, correct?
Now for the problem. Inquisitors are known as very strong allomancers. VERY strong. And we can infer from information provided that strength in allomancy is determined by the purity of the bloodline. This is also what determines whether one is a mistborn or a misting. So if you are getting your power from mistings, you should theoretically only have as much power as they do, as you obtained the power from the same bloodline they did. Mistings are more skilled with metals they work with, yes, but not stronger. Even if you used mistborn, it wouldn't work. Today's mistborn are not as strong as inquisitors either. We don't know how feruchemy works as far as genetics goes, but it doesn't work for allomancy.
Another question, assuming that I'm wrong, would a feruchemist give one feruchemial power or all of them?
And I don't think that using someone with stronger feruchemial or allomantic abilities would increase your power, because I don't agree with this particular theory. If you do agree with it, then I would say the stronger your sacrifices, the stronger you will be. Which raises an interesting question.
What happens if the sacrifice used to create an inquisitor is already a hemalurgist?
