I would prefer that if I asked a log page to refresh every 10 seconds, when I went back to it or any other log page, they also had their refresh times set to 10seconds

Whether this is maintained per user (being a web app i'm aware that's an issue) or just per session (probably easier) is not a problem. Personally if i leave the app and go back to it I don't mind as much if the refresh is reset. Or in a pointless options style, you could add it to the user preferences screen :s (it's an option, not a suggestion)