I'm not a trader who runs a business on eBay - yet - but I have used eBay since they first set up here in the Uk, and Yahoo auctions before that. So I have a fair bit of experience.
There are a few things to consider.
eBay provides a fairly unique service - it's a huge marketplace and has global reach, so it puts you in contact with potential buyers in a LOT of places. That in turn can increase your potential sale price (for an auction, anyway). This, to me, is its advantage as a selling medium.
eBay is NOT the company it used to be, and will never go back to being that. Auctions are an ever-shrinking part of its business, and private sellers are an ever shrinking part of its business. eBay absolutely wants to be the next Amazon - a universal online shopping portal. The point was made that eBay is effectively a monopoly and that is correct too. It has no competition and thus no incentive to compete for customers.
eBay doesn't do much if anything about dodgy bidders, scammers etc because IT MAKES MONEY FROM THEM! Every scam bid that gets cancelled, they make a listing fee on that regardless. Getting that refunded is a royal PITA.
eBay doesn't allow NF for buyers because it depends on buyers to attract the sellers who pay the fees... NF drives buyers away. The only you can do and MUST do is file a complaint for non-payment. Eventually after three strikes they get whack-a-moled and have to create a new account. It's not much.
If you are serious about being paid then it is basically up to you to take action directly. eBay can be sued but so too can the buyer (unless I'm mistaken) - a bid is a legally binding contract I believe. Suing 'customers' sounds bad for business but non-payers are NOT customers. But if you don't take action... they get away with it. And the fact is, I've never even heard of a bidder being sued for non-payment. The more people get away with behavng badly, the worse it gets. The fact is, we are all responsible in part for creating this situation.
As for blatantly fraudulant trades etc... go to the police, go to your solicitors. If the police say 'not interested' file a complaint! This is, of course, one of the fundamental reasons the UK sucks so much - because we (including as traders) are notorious for not complaining. The result is that corporations dump on us, rip us off, treat us badly - and get away with it. I'm sorry - but we ALL have to fight, all the time. that is the nature of life.
Another point - we are in a recession. There are more and more people getting more and more desperate and if hitting BiN to remove a competing auction for a few days helps, it will happen. Or hitting BiN and then trying to negotiate a lower price after the fact... etc. Get smart, and at the least make it clear in your sale conditions that the accepted bid price is FINAL.
Certainly block bids from people with no registered credit card and insist on immediate payment (doesn't work for items over £1000 though I believe). Forget 'PP for deposit, cheque for balance' as that plainly falls under their 'fee avoidance' rules and always has done. It's a loada crap, but can't be helped.
Yes, eBay/Paypal is expensive but if you seek out the advantages - market reach, basically - and avoid the obvious mistakes then you can still enjoy it. It's not for every commodity or item type. ANd of course as eBay gets worse, more sellers - and thus more buyers - go elsewhere. Amazon, for one, and also forums.
Forums, of course, carry their own risks... but generally seem to take trading standards more seriously.
Anyway, if you don't like eBay, don't use it. But if you make that decision, make sure that when you close your account with them, that you tell them why. No feedback means no chance of change. Do your part - complain!!!