Be careful reporting sellers or listings. It will cause your account to be closely watched.
Now, my biggest sellers are address labels. I sell them for $2.00. If I added tracking to my package, I would have to charge for Priority Mail. Maybe it is just my little post office where the post master watch for 1st class coming in with delivery confirmation. But, it is not allowed. Who is going to pay almost $5.00 for a sheet of labels? NO ONE! But, yet, if Ebay forces the issue, I would be out of business in no time. Most of my buyers are honest and I have no problem shipping again if they say that they didn't receive the first set.
And in 2005, I sent out a ring to a buyer. She stated in emails that she didn't want it and expected me to refund her before she returned it. She filed with Paypal stated she didn't receive the ring. I called Paypal. Copied all of her emails. She even put in the dispute that she received the ring. Paypal gave her the money and she kept the ring. I was told by the Paypal rep - if I can not prove I mailed it with a tracking number - I will lose everytime. This was before I used tracking on my other items. And I will admit that when I know for a fact that a buyer is trying to scam me and I didn't ship with tracking, I will send them a receipt with tracking and submit to Paypal. I have done this 1 time and would have lost alot.
There is a seller in Canada that sells counterfeit items, overcharges on shipping and brags that if she gets a paypal dispute, she refunds and then files non payment against the buyer. She has cursed at her buyers and even does so in her feedback.