Yes, the Admin/Insights links only show if you are the Admin of the page to be Like'd. I'm not sure why it's only showing on a few of your Like buttons, actually. We do have some changes in the upcoming 4.1 release, which may fix that. It's also possible that Facebook hasn't scanned all of your internal pages yet, so those Like buttons aren't associated with your admin yet. That can take up to a week from when you first add the buttons.
As for the width issue, you're currently set to 400 which seems like enough. It does look like you could eek it up to 425 though, just to test with. Either way though, in Firefox, I'm not seeing the issue at all. It seems to only be an issue that admins of your FB application would see (you). I'd definitely test while being logged into Facebook (in another tab or through your site) with a different user or not at all, and see if you can duplicate the problem. I don't think you'll be able too.. and if not, it's likely just an oddity of FB. Usually, these get cleared up quickly, but we can submit a bug report to them if it's really irking you
Hope that helps,
Alex