Bunkai...Oyo...Henka...or what?

If bunkai is the analysis of kata, what the heck is oyo? Someone I read said it was going beyond the basic interpretation of the moves in kata. How can you go beyond them? Someone else suggested that oyo was more interpretive, open to more imaginative analysis. That means making it up, doesn't it? Another person I was reading--someone who I believe would certainly buy into all these different terms--proffered the notion that bunkai itself has different levels, a beginner's level, an intermediate level, and an advanced level, and that oyo and henka were somewhere beyond these "basic" levels. I suppose henka is somewhere in the stratosphere.

Seisan kata:
If this is a "punch"
with the shoulder instead
of a fist punch, does that
make it bunkai or oyo?

The problem for me...well, there are a number of problems here. First: The people who use these terms define bunkai as the interpretation of a kata move the way it has always been interpreted or applied--that is, how your teacher and your teacher's teacher taught the application. But here's the question: What if they were wrong? Or more pointedly, what if they were never taught a bunkai for a particular technique? What if they had to figure it out for themselves? I had a friend in Okinawa--a third dan who had been training for 15 years--who had never been taught or ever studied bunkai for the classical katas. Then again, if you find an application for a move that exactly follows the kata move is it still bunkai if you find it? Most of the "bunkai" I see on the Internet doesn't apply the technique exactly the way it is seen in kata. Does that make it all oyo and none of it bunkai? When Morio Higaonna sensei steps back when he demonstrates the "bunkai" to the first technique in Seiunchin instead of stepping forward along an angle the way the kata shows, is that bunkai or oyo? And what about when he throws a front kick in? 

Secondly: At least some of the people I've read who use these terms define oyo as the practical application of a kata technique. What the heck does that mean? The implication is that they do the technique sorta the way it's done in kata, but if they need to take an extra step or anything to "make it work," then that's oyo and not bunkai. This strikes me as ridiculous. The kata shows you exactly how to apply the technique, steps and all. If the application requires you to do anything else in "practical application" then you haven't got your interpretation of the technique right in the first place. To suggest that kata preserves a technique but only shows it in a way that would be impractical in real situations is totally illogical. To persist in your interpretation that requires you to do something extra, but justify it by calling it oyo, is the height of arrogance. 

Seiunchin kata;
Is this a down block or a
down strike with the forearm?
Which is bunkai and which
is oyo? 

Thirdly: The people who use these terms define henka as a variation of bunkai, so I suppose it's a variation of oyo too. Does that mean it's a variation of a variation? Now I'm really confused. By variation, I think, they mean that you can get as far from kata technique as you want in applying your henka waza. This is where it gets wonderfully creative and, I must say, wildly entertaining. I recently saw a short "One Minute Bunkai" by some folks where the elbow technique became a block and fist punch to the opponent's elbow/arm. To be fair, this was called bunkai, not henka, because, I suppose, one of the guiding principles of this ryu is "attacking the 'branches' before attacking 'the trunk,'" as it says on one of their web sites. Hmmmm?! I go back to my original question: What if the bunkai that you've been taught is wrong? 

I think we should get rid of all these terms. I'm not sure whether any of them are historically accurate anyway. In Okinawa, whenever we asked the teacher how a technique was applied or what it was for, we just asked, "Sensei, imi-wa?" And I don't think it was just our rudimentary Japanese--my teacher still uses the term (imi-wa). I'm not against the creative interpretation of movement, but let's not call it Goju. The essence of Goju-ryu is contained in the eight classical katas (plus Sanchin and Tensho, I suppose), and if you diverge from the movement of kata or its intent, is it still Goju or is it something else of your own design?