Re: Who's your Teacher?
This is an interesting question because there are levels of meaning here. There can be a number of answers the asker of the question is lookin for...
If you are of relatively high rank, perhaps 4th Dan or above, you most likely have a Teacher with whom you are closely associated. Determining who that is would be the purpose of the question. However, in this day and age, things get a lot more complex. Many folks have broken off from their teacher and are unaffiliated or have re-affiliated wit another group or organization.
Mary Heiny Sensei would be an example of someone unaffiliated. Originally, she was a student of Hikitsuchi Sensei in Shingu (although she trained extensively with other teachers at the Aikikai Honbu Dojo in Tokyo as well). If you asked her who her teacher is she would probably tell you that hse had trained with Hikitsuchi Sensei but wouldn't go into more detail other than to say she is now unaffiliated.
Someone who isn't senior enough to go his own way with credibility will often re-affiliate. Toyoda Sensei's AAA Organization had a large number of people who had originally been students of other teachers. I always found that when one asked someone who their teacher was, if they responeded that they were under Toyoda Sensei, you always wanted to find out if they were originally his student or they had joined up later. This has to do with the intentio of the question. Most folks ask the question to get an idea of what your Aikido might be like. Saying who you are currently affiliated with rather than the person you spent fifteen or twenty years under doesn't answer that question well at all.
Then there are the folks that have a teacher who is not very senior. If someone askes you who your teacher is and you reply with Sensei so and so and he isn't senior enough to be known at all, the questioner doesn't often feel he found out what he wanted. He will often ask who your teacher trained with in order to get clarification. Aikido is such a small world that, unlike karate, it's hard to pretend that you are really senior when you aren't. So if the questioner doesn't get to a name he recognizes fairly quickly, he will make his own judgments about what your training may have been like (or he will simply suspend judegment).
Then you get to the group of folks who don't have a "Teacher". Perhaps they train in a dojo which is a satellite dojo of a lrage organization in which some senior person has been asked to oversee your program. The folks you train with are your instructors, your testing may well be overseen by this senior person, your rank may be certified by a Teacher at the home dojo whom you never even see...
When these folks are asked who their Teacher is, they have to reply that they train with a number of instructors who are within a certain organization. This can be the case even if you train at the Aikikai Headquarters Dojo. There are a large number of teachers there and it is quite possible to train extensively without having anyone of them be described as "Your Teacher". So you'd reply that you train at the Honbu Dojo and that you've trained extensively with Senseis X,Y and Z.
So, in the end it really comes down to whether or not there is a person to whom you feel you owe a degree of loyalty beyond what you owe anyone else and whether that person feels like it is his responsibility to oversee your training and help you move along in your ranking etc. If so you have Teacher and that's your response. If there isn't anyone who fits that bill but rather a bunch of folks you feel grateful to for their teaching atht isn't the same as "having a Teacher" which suggests a certain relationship.
It sounds as ig this is the position in which you find yourself. So I would simply reply with the names of the two or perhaps three people who have given you the most help and mention within what organization this is all taking pace and leave it at that. The questioner will now know what he wanted to know I think.