Well, to answer your question the best I can...
It's sort of both. Some of us made characters specifically for each others, where as some were made at random and put together, disregarding chemistry all together.
Since it's a small group of users at the moment, we do sort of take turns. It's almost implied since we usually do actions that involve other characters inputs. The turn system is sort of there, but it isn't enforced by any means.
And yes, you do, Admin has been working on many characters at once, and if they are finished I should go approve them ^^; SO to answer that question, yes, go ahead and submit your character under OC Submissions and myself or Admin or a Mod will look at it when it is up!
I hope that cleared somethings up for you!
Happy Roleplaying~
ClassicalMusician