How bidding works is at the moment kind of a black art, as far as I can tell. The story from Orlando is basically "if you want something, tell us, and we'll see if we can get it for you. Subject, of course, to our needs at the time." In theory, a more senior pilot can "bump" you from your run, I think. In practice, I've never seen this happen. This is largely because the more senior pilots already have runs they like, but also, I suspect, because there is no clearly defined "bidding" process. This is not a regional, where you sit down with your laptop and see what your seniority will hold. When I moved to my current base and expressed an interest in a certain run I was told "you can plan on that, but the pilots sort of work out who flies what on their own". Make of that what you will (I got the run I wanted, woe is me). Generally, once you have a run you want, you will not be removed from it. That being said the first month or so you could be almost anywhere. Mostly places other pilots have decided they do not want to be. Jackson and Birmingham seem to be extremely unpopular, for example.
I've never heard of a guy high on the seniority list changing his run. But again, since the process isn't exactly "transparent", I can only speak for my base.
As to pay, it's totally dependent on duty time. You can do five short legs in a row and make $19.5k/year, or you can do 2 legs and sit around all day and clear $34k your first year. Take this under advisement when choosing a run. Pay does not, to my understanding, go up a great deal, although there is some sort of raise after a year. Baron are paid the same basic rate as 210 runs, under the (accurate) theory that multi time is its own reward and you'll be moving on soon anyway. Also, baron runs tend to be shorter, so try to put something in the bank while you're on the 210.
