Re: Is it still Aikido if you take away the Japanese clothes, etiquette and other things?
A couple of people have mentioned school or military uniforms, but I didn't see anyone really get into *why* schools and the military require uniforms (it's late, I'm tired, I might have missed it). Part of the reason that schools require uniforms is that it makes all of the students look similar, regardless of their backgrounds. A person could wear pants with the crotch at their knees and their underwear showing outside the dojo, but when they put on the dogi they're just another student, no different from the guy who wears a business suit outside of the dojo. The military uniform is an extension of that, with internal rank added: the guy who usually wears the baggy pants might be a sandan, and the business man a gokyu, and their relative ranks in the dojo are broadcasted as different from their relative ranks outside of the dojo in part because of their training uniforms. For most humans, hierarchy matters even if it's not as overtly observed as in the dojo. Some other ranked, universal exercise clothing would also work... but, as someone else already said, why fix what ain't broken?
Another thing that people are touching on but haven't (as far as I have picked up on) completely elucidated is that what we do every day in the dojo isn't necessarily the same thing as what we do 'in real life' or 'on the street.' If we execute a technique on a drunken guy at a party without bowing to him, it might or might not be 'aikido' but whether or not it's aikido doesn't have much to do with the presence or absence of a bow in that case. On the other hand, if you *almost always* or *almost never* bow while training in aikido, I think that will impact your overall practice and whether or not you should consider it 'aikido.'
apologies if I'm rehashing things that have already been discussed.