How to refund airline tickets?
Request your seat preference (aisle or window) when buying your ticket. You could find yourself with a middle seat if you wait until check-in. SeatGuru.com has detailed maps of the best and worst seats on specific planes, so you can avoid seats that don't recline and keep an eye out for those with extra leg room.
Baggage allowance depends on the airline and type of flight.
How to exchange airline tickets?
Consider flying through a secondary airport. Orange County and Burbank are alternatives to LAX, and Newark International can substitute for the busier and oft-delayed JFK or LaGuardia airports. You may have to drive further, but if flights are impossible to get or impossibly expensive, you might be surprised by the ease of use and friendlier prices of smaller airports.