Nothing much has changed, all new members start with 0 feedback.
You say you used Special Delivery so how can buyer claim not received? If it really was not delivered, tracking would serve no purpose and you would have to refund buyer and then claim from Royal Mail.
If buyer claimed damaged/not working nothing has changed, you would end up paying for return postage and on return refund. There has always been some abuse of returns, and ebay rarely even investigate but just find in favour of the buyer.
Having a proper return system is sensible, as No Returns invites abuse of the return process.
If you consider selling is risky then ebay is not the place for you.