Re: ettiquette question
Interestingly, at my main dojo we don't line up according to rank, but more like free-form staggered columns. My instructor tells new people and non-ranked folk to sit in the front, to see better. The kids class before the adult class does line-up, but it seems to be a mixed bag.
At the other dojo I've trained at, they did line-up according to rank. But at the beginner's class I participated in at Aikikai Hombu, everyone lined up where there was space. I tried to place myself at the end of the line, but a hakama'd fellow lined-up to the left me anyway.
In traditional Japanese etiquette, the basic rule of thumb is that the guest always takes the humblest position, and the host always tries to exalt the guest. So when you enter a house, and the host tells you to sit down, you choose the shimoza 下座 "low seat", the seat facing the tokonoma or (similar shelf) and closest to the entrance. But, when you are the host, you are supposed to tell your guest to sit in the kamiza 上座 "high seat", the seat nearest to the tokonoma and farthest from the entrance.
This would translate to the dojo as a guest choosing to sit at the end of the line, unless invited to sit elsewhere by the instructor.