"Do committed aeromodellers think that non-aeromodellers are bad people, and totally wrong in all their thinking?"

No........but a few of them assume that they are way "cooler" than people who don't aeromodell. There are a few pompous assholes in every broad category of people... ;-)

An atheist is someone who doesn't believe in a "God" or "Gods". (theos = god)

A theist is someone who does believe in a "God" or "Gods".

However, it doesn't just stop there, because there are an infinite number of ways of defining "God", and some of those ways would make God enough like a Universal Principle or a Natural Order of Things that it would be hard for even the strictest atheist to reject them out of hand....IF he understood them in the first place...which he probably doesn't...because he's never really given it much thought.

Atheist, in other words, don't really object to ALL possible definitions of "God" (in my opinion), they just object to the simpler and more traditional and literal definitions of God which they have encountered generally and are familiar with.

They object, generally speaking, to "God" as God is superficially presented to them by the conventional churches and outwardly religious people in their own society. The "God" that's most noticeable, in other words.

It's kind of like Americans objecting to "socialism", although they barely even have any idea what it is. ;-)