Strong schools of thought stand both for and against your posting. I did some selling on here a few years ago now and one buyer took nearly TWO WEEKS to pay and without communicating to me why this was. The pair of items they had bought cost just shy of £60 and so if they were on Social Security Benefits and couldn't pay ... Why not just tell me I'm not inhuman?! Well the option I was left with was to leave them a positive feedback as Sellers by then could only leave positives for buyers but included 'Slow Payer that does not communicate well' in my comment. I heard nothing back about either items - positive / negative - nothing so I don't even know if they were received even ... 
Retaliatory feedback has only been a problem I have found with people who appear to be unscrupulous ... Or if the Feedback comment made out in itself that it's retaliatory. EBay removed an unjust comment with a friend of mine which was made by a buyer after he had left them a relatively generic 'Super EBayer - Thanks for your custom' type comment as a positive when they paid for what they bought. The only time prior to 2006 when I encountered the 'retaliatory' one was when I was left a negative as a payment sent by postal order as I didn't have a bank account at the time took two weeks to be delivered by post. The comment left for me called me names and at the time NPB stood for 'Non-Paying Bidder' ... Not something commonly seen nowadays. So I left a negative as the buyer in reply saying impatient and rude seller who left aggressive swearing all over my Feedback. Both comments were removed by EBay and anyway that guy isn't on here any more. Retaliatory? We are all entitled to our opinions but what do you reckon in your opinion - was it. There is an option you may be aware of to 'Follow Up on Feedback Received' where you are able to leave one reply in return for any feedback comment received. Here is where you can return fire with 'Retaliatory IMHO - Uncalled for' or something similar to make the person look like the unscrupulous individual that they are. But I think opposing that is that EBay doesn't want this to blight this site on a regular basis or too often. So as some form of deterrent the options for doing so are not present right from the start 
As a buyer to a seller if the buyer pays at lightning speed like I MUCH prefer to then the seller has left a comment saying so most of the time in the trust that being satisfied with the item I will do the same: This is what I do and that's all part of the goodwill and trust factors that I think have to be an integral part of EBay transactions. If I get unscrupulously 'DIDDLED' by a seller who sends me rubbish I will not send Feedback but go to the Resolution Centre and / or to Paypal first - in the interest of demanding answers for their conduct. Only upon the case being closed and especially if it doesn't look as if a genuine mistake has been made do I then leave negative feedback telling the truth 
I agree that by altering such aspects as you point out that EBay is trying to eliminate the need for 'trust' and 'goodwill' / 'integrity' to have to be present within transactions but IMHO they never will as this is not the high street. You can never tangibly 'try before you buy' or even check the item yourself before going ahead and parting with your cash: So the need for 'Trust' and 'integrity' will never leave this equation however hard they try to make them. All I can now hope is that this will be helpful to you in some way - I sure hope so. Have a nice day 
