...I to this day have never seen anything in JKD that I have not seen in all other styles...
Bob,
I agree with your statement with one exception. The JKD Lead punch. When you see someone throw this punch, it does not look any different than other arts. But once you get into the mechanics of it, it is a punch I have not seen in any other martial art. Many of the mechanics are the same, but the total approach and sequence of motions are unique to JKD. At least from what I have seen and experienced.
As to the rest, there's not much difference in the tools. As you said, the mindset is the difference.
But, is it a style with its own set of techniques, philosophies, etc.? Some say that JKD is only a philosophy and can be applied to any art. Many of these people disregard any of the techniques and mechanics that Bruce Lee taught as JKD.
Then of course, you have those that say JKD is ONLY what Bruce Lee taught and therefore it is a style with technical boundaries.