To get back on the topic...
USA
Ladies: If Sasha stays for the season, I believe she'll be the favourite. If not, Kimmie. Katie and Emily will be the underdogs.
Men: Unless Johnny improves his consistency, Evan will be the favourite.
Japan:
Ladies: Mao - the favourite, Fumie - the underdog, Yukari & Miki - the blackhorses.
Men: Nobunari & Daisuke will be the favourites, with Takahiko Kozuka as underdog.
Canada:
Ladies: Rochette and Leung, respectively.
Men: Sandhu had slight edge at Worlds, but I believe Buttle will keep the status of the favourite, unless the GP shows otherwise.
About placement at Worlds, again, I bet he would be prouder to be Japanese champion than to place 5th rather than 8th at Worlds.
I think the international results do matter for him, because they show how well one can perform under the pressure and pitched against the best. What's more, high international placement guarantees more recognition. I believe he wanted to grab a medal for Japan. When he ended up just a few points short of bronze, he said he "would not be able to return to Japan with a smile on his face", because his fellow countrymen were counting on him to bring home silver or bronze.
IMHO the National title doesn't have quite as much prestige, if only because there are many national champions who are poorly known because of their unability to place high at Worlds or Olympics. Of course, in the majority of the countries the national champion title is very much desired, as it is the ticket to the international competitions. In Japan, however, what matters the most is not the title itself, but the amount of points gathered during the season.