On the bowing issue...
I came from a dojo (non-Aikido) where we all bowed to our practice partners before and after any practice session, but it was a standing bow. We never really bowed to our teacher, or to any pictures, etc.
But when I moved and was looking around at various dojos to train at, I found that I was pretty wierded out by the kneeling bow, especially that done towards the picture of O Sensei, and the teacher after he demonstrated any technique. Why? It had to do with my understanding of the purpose of bowing. I had been taught that you bowed to your partner before practice to show thanks for their willingness to train with you and help you better understand the techniques. You bouwed at the end of practicing with them to thank them again. But it was always a bow between (roughly) equals. Even across rankings, we were all helping each other learn, in roughly the same way. Bowing en masse to a teacher would be an acknowledgement of superiority... something that perhaps would be deserved, but my teacher vehemently opposed, since "we are all students", or all "just human beings"
Needless to say, bowing to a picture en masse was even more alien to me.
Over time, I have gotten used to bowing pretty often, and it's not quite as "wierd" to me, but I still regard the process the same way.
If I at some point (years from now, likely) to begin teaching, I would like to say that I wouldn't require any bowing except between each other. Unfortunately, it might well not be true for me, mostly because by the time you have achieved a significant rank in Aikido, you are bound within a web of social connections which hampers your ability to act entirely independently of the decisions that your teacher makes. I have seen a few examples of this, and wonder how many people would still require bowing of specified depth (kneeling vs. standing), and at certain times (beginning of class, after techniqe demonstrations, to partners) if they were to be making this decision independent of the approbation of the Aiki community.
Useless question, but a fun one nonetheless.