Out of curiosity, why do you feel that PayPal, Amazon Payments and Google Checkout are all so evil, that putting $10 into them is unthinkable, even if it means supporting charities like Child's Play, the EFF, and Indie Developers porting their games to Linux and offering source code?
Full disclaimer, I work for PayPal.
I'll talk about PayPal, not having had much experience with AP (some) and GCO (none).
Let's start with the fee structures. I can almost understand transaction fees for credit card payments given they are passed on to Visa/MC (though I am sure PP does not pay anywhere near as high transaction fees that they charge others). However, for payments from PayPal balance, the fees are atrociously high for not a lot of benefit. This is untenable if you want micropayments, and is really f'n annoying for stuff that is not "micro". When I give the recipient money, I'd like them to receive almost all of it -- possibly commensurate to the actual fees Visa/MC extract with a tiny percentage and no per-transaction fee for PayPal. Right now you're fleecing on balance-payments.
Dispute Resolution -- it takes quite a while. It may have to. Over the years PP has improved on this a bit by opting to freeze specific transactions and not entire accounts -- though this is at the whim of whoever decides something is "suspicious".
Moreover, looking at it from the perspective of a seller, if you want to keep your account, you are pretty much pressured into acquiescing on any and all disputes. PayPal, while charging a LOT of money for their services, shifts the responsibility for fraud towards the recipients of any transaction. Considering it is an eBay company, this is rather an interesting choice -- if I sell something on eBay and the buyer complains about not receiving his item or receiving a degraded version thereof, there is nothing the seller can really do to disprove this -- in the case of physical goods there may or may not be a shipping slip (but let's get real here for a minute, for private transactions the cheaper shipping options do not always provide those) which PayPal may or may not accept -- if you go "digital", there is nothing you can show. If a seller receives a dispute notice on a transaction, they can write it off right then and there. No chance in hell PayPal will eat it. Notice how this also does not give PayPal any incentive to increase account security, fraud protection, etc. You can claim that PayPal "cares" about this regardless, but why should it ?
PayPal acts like a bank, holding a balance, freezing transactions, etc -- at the same time it does everything in its power not to be regulated like a real bank in most jurisdictions. If I go to a bank in Germany to do a transaction, there is regulatory oversight with teeth in these cases. PayPal ? Fat chance.
There have been enough cases of PP freezing recipient accounts entirely; they may state a reason, but that's not worth the email it was sent in. This seems to happen when an account suddenly gets a bunch of payments from many sources. Maybe this has changed and ONLY the "suspicious" transaction are frozen now, but given history, I would not bet on it. Specifically, I would not want to use PayPal for any purpose where there is a possibility of a decent influx of transactions. I can go down to my bank's main offices and resolve issues in a matter of hours, if not minutes, should they really arise. I cannot do so at PayPal, and it can take weeks for them, dragging their feet.
Unfortunately some of the directions PP is going in are the same directions other payment/cc networks and regulatory bodies are going; as such your suggestion to use cash wherever possible is one I try to follow where possible. Businesses actually often prefer it -- the marketing blurb goes that handling real money costs more money than handling credit card or debit card payments -- this may be true if that is all you accept, ever, but if you accept cash (and who doesn't), you have those costs either way and save on the transaction fees (which are considerable especially for low volumes). In addition I actually get true anonymity. The amount of bullshit and crap spam even moderate use of eBay will yield to your inbox