It will be a little small for your family. You can check for bigger room.

I am sure they can accommodate your need since while we were there, one of the tour guest request vegan breakfast and the manager specially prepared for her. You'll have to put in the request when you do the booking & once you check in then ask to speak with the dinning room manager. If you are a schedule in the morning you'll inform them what time you'll take your breakfast otherwise they won't have the breakfast on time

Totally worth it especially with children (we had our 15 mo old with us). When we stayed in Kyoto it cost us 800 yen per luggage to forward it to another hotel in Kyoto. From Kyoto to Kansai International, it cost 2700 yen per luggage. They can send your luggage pretty much anywhere, just be aware of time (ie, if you're forwarding it to somewhere farther away, you might have to give your luggage a day or more ahead of when you expect to arrive at your next destination). Also let the place that will be receiving it know that you're luggage will be sent to them.

you wont notice much noise and its only during the day