>Driver's License
They're asking about a Canadian one. You can get an international driver's license from the CAA which you can use for up to 1 year in Japan though.

>Intercultural experience
Yes talk about your Aikido classes, especially the traditions part, that will look good

>Proposed direction of career
Yeah, don't overthink it, if you want to work in translation talk about why you want to do that and how JET will help you (aka, practice in Japanese, learning nuances of the Japanese language, interacting with Japanese people, etc). You can also mention other positions where knowledge of Japanese language/culture would be useful (like embassy or international business) if those interest you

>Placement requests
Of all the things about your application that can affect where you get placed, the requests are typically last (except for medical reasons). Tokyo and Osaka get a ton of people requesting them so you are statistically less likely to get placed there. Anywhere that you do request, you should be able to back it up, since you may be asked about it on the interview. If you put prefer urban they will ask you "How would you cope if you get a rural placement?". I would say you can put semi-urban (I believe that was an option). That essentially means suburbs. Most of the placements will be suburban and you will have all the amenities that the cities have, but they also won't be as crowded or expensive.

Things that are marginally more likely are sister cities. If your hometown in Russia or some other place you've lived has a relationship with a sister city in Japan, you can put those cities down. If you're super keen you can even contact the sister city directly and let them know you are applying for JET and would be interested in working in their city if there is a position open there.
But that's also not guaranteed. I requested two sister cities on my application and wasn't placed in either of them.

Be careful with Islands. You should understand that there is going to be a lot more isolation if you're placed on a smaller island in terms of community. It will be harder to get around the country since you will rely on fairies, and there definitely won't be as many "comfort" options, like foreign foods/non-Japanese people/ entertainment/activities around. On the other hand you will probably get more integrated into the local culture, out of necessity. So you can request that if this kind of experience interests you and you can handle the downsides.

Glad to help with any further questions.