Re: What makes a style?
I ultimately agree with your Shihan that there is no style beyond the individual, but I agree with the point I think you're making. I know there are styles of "Aikido" which claim no association with Ueshiba Sensei, which was very confusing to me when i first spoke with some of them. At first I simply refused to call them "Aikido." But now I basically take everything with a grain of salt. Coming from a rather rare "style" myself I guess I have to.
My concern isn't so much raised when i think of fairly experienced students, but it is when i think of neophytes who have little to no initial perspective. With that in mind, whenever I describe Aikido to people who are interested in learning it, I try to encourage them to see as many different styles and schools as possible. The first time I trained at a different dojo from my own I found out how diverse the lable "Aikido" can be, whether one is talking about martial application or philosophy or whatever. In fact, when training with different people within my own style I sometimes get a very different feel for a given technique. One person would tell me the "real" trick to the technique was such and such, and then another would tell me something different.