Hello, I'm new here, so I thought I'd introduce myself with a new Hogwash word.

It's "conurbation."

If that word is too well-known, I shall choose another.

1. conurbation can be found in 18 general dictionaries at OneLook.com (including M-WCD and AHD4), plus it's been used by Anu for AWAD. so I'd say: yes, it's much too common.

1a. the actual meaning would be *way too easy to suss from its roots.

2. we usually let an ongoing game of hogwash resolve itself before we start another; but that's just local convention I guess.

edit: added 1a.

...and welcome to our merry madhouse!

that's just local convention I guess.

I have attended local conventions. My experience is that people are more constrained when attending a convention in their home city than they are when convening far away from home. It is kinda like that whole "What happens in Las Vegas stays in Las Vegas" sorta thing.