Re: Is it still Aikido if you take away the Japanese clothes, etiquette and other things?
Well, in my opinion, if you strip aikido from it's etiquette, protocol and dressing it wouldn't be aikido anymore, it wouldn't even qualify for a true budo.
Aikido is not a matter of personal definition but a complete martial art. There are people who are making convenient choices based on their personal opinions, so we have schools that practice no weapons because it seems useless, schools that don't adopt the proper etiquette, because they see no point in it but then these choices are showing badly on their technique.
You can make, serve and drink tea without performing the tea ceremony, it would taste the same. But you cannot call it "tea ceremony" anymore it would be mere "tea drinking". In the same manner you can practice kote gaeshi effectively without the etiquette or hakama. It can be a good disarming technique and combat method. But it wouldn't be a martial art anymore.
Studying the culture of any country by reading books is a very different thing from practicing a martial art as a way of life. Stripping it from any of it's core elements out of convenience would only leave your practice poorer...