I'm not up to speed on all the variations of the bank card charges, but re: frequent flyer programs...
They are all "subject to change" and, as everyone knows, these changes have frequently included decreases in the way miles are earned and increases in the miles needed to get a flight or an upgrade, as well as any other "conditions" they wish to impose.
It's been a while, so my information may not be fully accurate, but I seem to recall trying to upgrade to first class on some United flight and being told that the particular discount fare I had booked was not upgradable with miles, but for the difference in ticket price I could buy a different fare class which would be eligible for upgrade with miles -- to me, that's exactly the same as a (in that case, significant) fee PLUS miles being required to use your miles. On another occasion, an agent told me that I should have been able to upgrade ANY purchased ticket, so it could have all been a mistake.
And of course, recently many of the airlines have gone to charging a fee on top of the miles to book a frequent flyer flight, and sometimes the fee is much higher for "late" reservations, although I think I recently read of some airlines getting rid of those "late" reservation fees.
Finally, of course, the airline controls how many seats are available on a flight for those flying with miles, and I don't know if there is ANY regulation whatsoever guaranteeing a minimum number of such seats on every flight, but there certainly can be very few such seats available sometimes, and in those cases, particularly for the most desirable destinations (e.g. Hawaii), those seats can fill quickly.
On the flip side, during the one or two years of my life when I was a VERY frequent flyer, I could call my favored airline and get sent up the staff line to a supervisor who could make a phone call and arrange for a couple more mileage seats to be opened up, in order to accomodate me -- but you have to be a very favored customer to get that treatment (it was fun duing the brief time I qualified, I assure you -- notes from the pilot on his business card thanking you for your business, etc., but of course the biggest benefit is getting in the short lines, when there used to be ticket agents for airlines at the airport, instead of machines).
My biggest fear for changes is whether they can completely shut down a program if they go into operating bankruptcy; I don't see why holders of miles might not be treated any differently than other "creditors" of the airline, and can visualize a bankruptcy court "paying" mileage holders at 10% along with the other creditors, or "freezing" the programs -- any of which, like frequent player points from a casino, would be a loss of side benefits that added value to being a customer.
But, in (partial) retirement, I drive a lot more places, and no airline any longer thinks I'm "special" 
By the way, I recently received a charge card application from an airline with a "free" membership in their lounge club / program -- of course, the annual fee for the card is $375.
--BG
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5a. XVP - Caution, Be Aware of US Air's and Affiliate's Dirty Tricks
Posted by: "pesach kremen" royalflush2222@yahoo.com royalflush2222
Date: Fri Sep 4, 2009 10:43 am ((PDT))Being that US Air maintains a hub in Vegas, many of you probably are US Air
Frequent Flyers as well as have their US Airways Master Card. Furst of all, US
Air noiw charges a fee for ticketing frequent flyuer awards, regardless of how
you ticket it, including well in advance, online, etc, unless you are in one of
their "preferred" categories. What is interesting is that when most joined th
eprogram this was never mentioned (as the fee did not exist) but now as you wish
to use your miles you have to pay. So much for a "free" ticket. Even worse is
their fee on fee structure with their US Airways Master Card. L:et's say that
you rcredit limit is $1,000 and you have charges of $930 on the card. The Annual
fee of $79 is now imposed bringing you to $1009, but since you are "overlimit"
now you are hit with anoher fee of $39.95. On toip o fthis they raised the
interest rate 4% on many of their cardholders, on balances you already owe!
They are doing htis now
as this practice will beillegal in 2010. Watch out! This is as bad as the taxis
in Vegas that illegally take the tunnel from the airport to rip you off!