Re: The uke/nage paradigm
I tend to agree with Demetrio... It sounds like your dojo has an identity crisis.
As a larger observation to the roles of partners, I think it is important to have a curriculum to which everyone adheres. This would be the role of Shidoin - to develop and enforce a general curriculum amongst the teachers. Back to my comment about kata... If you experience many different general expressions of kata, then your dojo may not be as clear in reinforcing kata. On the general level, everyone should understand their role in kata and be able to perform the same kata with everyone (and that kata should work within a bell curve of effect). On a personal level, students are granted the opportunity to express their variation of the kata. Technically, this expression would be the first step in expressing waza because it should be varied by the uniqueness of the relationship. But that leads back to the question, "Are you practicing kata, which all of your partners should perform with similar consistency. Or, are you practicing waza, which allows for some variation from your partner."
I think we run astray because our general kata is not precise. Either my hand is up, or its down. If it is specific enough to exist in kata, than we have an obligation to perform the kata as demonstrated. Here's the beef - Aikido has a lot of bad kata; varied by organization, school, instructor and student. Not to bully on aikido, other arts have this same problem.
I can appreciate the frustration because it happens a lot, especially at seminars. There is a difference between sharing your personal perspective on waza and performing kata. Or performing waza under the direction of the instructor. This is a large complaint with seminar instructors. How many times have you heard at a seminar the instructor lament, "please try what I am showing. Go back to what you do when the seminar is over." or some variety thereof.