Re: Is cleaning the dojo part of training?
Hmm. I think being prepared to help in the dojo with cleaning reflects an internal attitdue which is also useful for performing aikido effectively. I think it's most accurately expressed through a concept of 'impartiality' i.e. if you are not partial to yourself you will not try and 'beat' the opponent, and thus are better at blending. Similarly it is easier to see yourself as a functioning and integral aspect of your environment and society and you don't have the feeling that you are 'loosing out' by cleaning.
However there is a difference between humility and submission, and I think much of japanese cultural structure relates to a strong hierarchy where the lower ranks are expected to be submissive.