Interesting. I haven't thought of Ultraman as a member of the monster fighting team, but you are right. And I don't remember it being touched on much in other series, but Ultraman directly tells him that he has to keep the fact that he can transform into Ultraman a secret from everyone. I see that as a lie of omission, which, to me, isn't as bad as outright lying (although some human hosts actually say that they are not Ultras when asked/accused directly, but usually because they are in a panic so I forgive them, too).

While I'm sure he didn't see it as a hobby, Ultraman 80 did try to fight monsters only part-time, but of course that didn't work out. ^^;; Although I think it could have worked if real-life pressure didn't cut out the school plotline from the show. Now I am left to dream of what could never be. Well, I guess it's for the best, because, as you say, it makes sense that those defense team members should be available all the time to fight monsters (they are similar to doctors and police officers having to be on call, I suppose).