re: Definitions
In common usage, it probably doesn't make much difference. I'm also a little gunshy from a number of years ago when O'Neill colonies were a big thing. Just using the word "colony" near a campus would have the leftists on your back like rabid spider monkeys.
I thought up the magnetic suspension system that would allow O'Neill colonies to be almost any size without exotic materials. In practice, tolerances would have been a problem, and frankly, I'm leery of active vs. passive systems.