Re: Knife Work
Some very good posts on this thread, and I can't add much to what's already been said.
I will say that I disagree with the definition 'knife-fighters' in general... this suggests someone who has experience in fighting with knives, meaning both people had knives and are trying to use them to inflict damage on each other... this in itself is a romantic mindset: the number of people with this kind of experience is by definition very very low, and the chances of you meeting one even lower.
If you are talking about people who use knives with the idea of harming other people you are talking about FMA teachers and students, criminals and the armed services. They are not knife-fighters, they have specific goals in mind, and neither 'killing' nor 'injuring' is not the same as 'fighting'.
As a specific answer to the original question: I think using aiki knife techs against a real opponent will likely exacerbate the situation and get you stuck. I've met very few people who use knives in the dojo anywhere near the way I've seen them used for real. The aiki knife techs are based on obsolete stylized attacks belonging to a certain place in history and geography IMHO.