I've finally (at a reasonably young age, I hope) started to pay attention to frequent flyer programs. In the past I've simply booked whatever was cheapest and not worried too much. I'm based in Chicago (nearer MDW, but a lot of my favorite routes have been cancelled in 2008) these days, and now travel about once a month -- to LGA and SFO mostly, but also to a lot of more random places (I am an academic, and also my family and friends are all over the world.)

I was wondering if people had some rules of thumb they'd like to share. In general, I've ended up accumulating most of my miles on United and American, but far prefer American's service (and their laptop ports, which are on all the flights I've taken with them.) One thing is that I don't plan on getting a miles-reward credit card.

Here are three basic questions, feel free to just paste a link or two; I'm sorry if they've been covered to death, but in browsing flyertalk I feel like a high school kid in a graduate seminar.

1. I travel domestically (usually on discount fares) perhaps fifteen times a year, with a few international flights in the mix. Am I ever going to make these various "exaulted" status tiers? What's the tipping point in terms of travel volume when you can reasonably expect to get there? Are there alternate routes to getting some of the "perks"?

2. I'm generally skinny enough to not mind economy, but one thing I do appreciate, especially since everything these days is delayed an hour at least, are the "first class" lounges where I can get work done. Do folks have suggestions about how to use mileage and so forth to get access to these?

3. I find all of the rules for FF credits and awards really complicated (I suppose they want them that way.) Sometimes I'll find a flight cheaper on an airline I don't usually travel (usually one of the budgets, or through priceline or STA); what is a good "rule of thumb" for paying extra for a flight one is accumulating miles for? Say an ORD-SFO American flight is an extra $50 over JetCheap; will I generally end up ahead in the long run by paying extra to get those miles? How about $100?

For example, I was going to book a near-full fare ORD-CDG for $750; I found a deal through STA for $600 but it turns out the booking code is Q and there's no mileage credit for transatlantic flights on that code. Smart, or foolish?

Additionally, I am curious (this is not a FF question, so maybe I should reroute) to learn more about how to "voluntarily" bump yourself off a flight. Only rarely have I heard the gate attendant announce they want to bump you, but you folks seem to talk about this all the time! Can you bump yourself to the next flight on the same day? Or do you enter some sort of limbo where you could leave the day after?