Honestly? Everything above is true. But I wouldnt do it. Its bound to attract the wrong kind of attention.
I do it all the time, and every time I travel by air. No-one even gives me a second glance, and if they do (passengers), it's their fear and paranoia that is doing that. If they don't know the reasons or motives behind you bringing your scanner, they can't judge or accuse you of doing something illegal. At the absolute worst, all they can do is ask you what the scanner is for. Give them an answer, and that is that. There is no rule stating that it can't be brought onto a plane. there is no rule stating that it can not be used in the airport. the only rule is that it isn't on the list of electronic devices that can be used while the plane is in midair. Other than that, they can not do a single thing to you for having the scanner with you.
So, which is more important: your right to use a device in which you would be in the right to use in the appropriate places, or cowering under someone else's FUD?