JPR reserved seats

Hi!

Basic questions about JR trains and JPR after reading the excellent japan-guide guide.

1) Can we reserve seats in all our future trips from the same ticket office at the same time (i.e our first visit to a JR station when exchanging the voucher)? Or just the ones that departs from that station?

2) In case we decide to go with an unreserved seat, do we need to visit the ticket office right before the departure or we can just pass through the gates showing the JR Pass?

We are travelling in late august and early September. Some of our rides will be Kyoto-Himeji, Himeji-Hiroshima, Hiroshima-Osaka, Osaka-Kyoto, Kyoto-Takayama, and Kanazawa-Tokyo. Some of them weekends, some of them weekdays.

Do you recommend that we reserve seats in all of these trains, or we can go easily unreseved? Any critical one?

Thanks a lot!

1) Yes, you can reserve all your seats for those trains for which you are available to reserve, but if there is a long line of people who wish to exchange the vouchers, the personnel will either ask you to only reserve a few trains or tell you you need to do it at a later time. This is especially true at the major airports, especially Narita, where many people will queue up. It's also best to have a list of exactly which trains you wish and also a priority list of the trains you wish to reserve first in case you can't do it all at once. Of course, common courtesy dictates that if there are many people behind you, you wouldn't wish someone ahead of you to reserve 30 trains while you wait and possibly miss the first train into the city.

2) Yes, you can just show your pass at the manned gate and go to the platform to wait for your train in the assigned queues.

Thanks a lot!