I'll Give The Questions A Shot
· How to get your reservation put on priority status;
This probably refers to either reservations waitlists for upgrade/reward seats, etc. It could also refer to placement on the airport standby list. For example, some airlines have special priority placement on the airport standby list for misconnects or other disserviced customers. An airport agent, if they want too, can put you on a higher priority part of the standby list. If you are already say a top level frequent flyer then you already get priority on the standby and other waitlists. You should also know that when reservations puts you on a waiting list for say an upgrade, they will sometimes imply that this list gets reviewed by someone who will decide if you clear. However, at some airlines the lists only get reviewed by computer software unless an agent calls in to revenue/yield management department. I know that for example 5 years ago or so CO international upgrade waiting lists were only reviewed by computer software unless a specific agent asked inventory management to get involved in a particular PNR, etc.
· How to get a refund on your ticket even when its non-refundable.
Airline agents can refund even nonrefundable tickets. This is most often done at the airport where agents have more discretion. Sometimes this is called an "involuntary refund." It is officially done say if your flight is cancelled or somehow interrupted. Also let's say you are flying LGA-PHL-LAX. Your LGA-PHL gets delayed so much and you miss the connection and suitable later flights to LAX. Because you've missed this connection you have such a short trip that it is not even worth you going on to LAX, and at PHL you just elect to hgo home to LGA and forget about the whole trip. You can be issued what is called a "trip in vain" refund. You will get miles for your LGA-PHL and PHL-LGA but your ticket is refunded because your trip was in vain. Sometimes in other involuntary refund situations an agent might write "trip in vain" on the paperwork. To answer your question directly though, an airport agent has the power to refund a nonrefundable ticket. If you can convince them to do it, or if they like you, the refund is yours. Sometimes when this is done as a passenger accommodation it will be coded in the computer under one of the officially sanctioned involuntary refund categories. For example, an agent is giving you an involuntary refund because they are a nice guy, they might code it as a weather involuntary refund. It is not worth any airlines time to scrutinize evry single transaction, there are thousands or hundreds of thousands of transactions "in the system" on any given day.
· How to get a larger seat when boarding the plane.
I take it this involves either getting a coach seat, for example in United Premier Economy, or an AA seat in the more room throguhout coach section which actually would have been all seats. It might also refer to getting a courtesy upgrade to first class. Again, airport agents can upgrade people if they want too. This doesn't mean they'll upgrade you, but if you make some connection with the agent, they have the power in the computer to upgrade you. I have even heard of situations where passengers get courtesy international upgrades, although it is generally easier to get upgraded domestically. Of course, per airline rules, agents are only supposed to give out upgrades in particular kinds of situations like to preferred level flyers, etc. But they have the technical authority in the computer system to upgrade virtually any ticket. So if you can sweet talk the agent, you might score a courtesy upgrade, or just if the agent likes you. You know, there is the whole thing the first few seconds you see someone, some kind of internal process runs in the brain and decides what kind of vibe you have with that person. I would not recommend you count on these random courtesy upgrades, but at the same time, be aware they do happen and if you put yourself in the right place and have a little luck, one might be yours. I would imagine the book might also educate the reader about the varying levels of frequent flyer programs, and how with each level you get more official upgrades too. Remember, the average person does not even know the mechanics of how each frequent flyer program has varying status levels, etc. The average person probably doesn't even try to stick with one airline for there 5 trips a year.