In spirit it is drop shipping, to the customer it looks like drop shipping, it takes as long (if not longer) than drop shiping, the price is as if it is drop shipping. You're a local seller drop shippig in my opinion.  But whatever the case, you need to consult with Trade Me to get their determination.

As you have tracking showing it was delivered, trade me won't do anything.  If he posts negative, ask for tm to remove it, you might get lucky.  He would have to take you to disputes tribunal to do more, and as long as you are a private seller he would not likely win.   In short, don't worry about it. 

Poor form Trade Me, poor form. I can't even see an obvious way to get to the edit your profile details unless you have made a post and so can find that post and click your own name in the post. I had to go digging through my email notifications to find a thread I had participated in to find my post to click my own profile to find the field to edit.

If the purchase is from an in trade seller, you ask the seller to send you a receipt. If the purchase is from a private seller, go to your Won Items https://www.trademe.co.nz/MyTradeMe/Buy/Won.aspx click the listing title, and print that page (or print as a PDF). If you are GST registered you can claim the GST on    1. New items sold by sellers who are GST registered   2. Secondhand items sold by anybody (doesn't matter if they are registered or not)      

If you are selling your own things that you just no longer want, you are not a business. If you buy (or make) something with the intent to derive a profit in doing so, then you are in trade, a business, and you are required to do the necessary things such as but not limited to...   1. pay tax on your profits, and ACC levies on your income   2. abide by the Consumer Guarantees Act   3. potentially charge and remit GST on your sales   4. potentially get a 2nd hand dealer's licence In terms of #4, see this page from the Police for the specific criteria.... https://www.police.govt.nz/advice-ser...

Yes ping is worth it. As a buyer I much prefer to pay with Ping, and as a seller I much prefer to get paid with Ping.  So do my customers it seems because at least 95% of my buyers would use Ping. Edit to add:  After Pay is a different story though, I don't know that really is worth it, I only get a small number of buyers using it, and the fee is substantial.  

Indeed, and as for the selecting your courier, they did mention that they want to present applicable shipping methods to the buyer, so that could conceivably be used for rural-not-rural or PO Box filtering of shipping methods for example... but as Callum says doesn't appear to make any difference currently. Here is the Webinar for those who missed it: https://www.youtube.com/watch?v=bUdRLe0Eh0g  

Trade Me advised today that they have implemented non-rural/urban only options now. That should make it less of a problem for many of us.

The search has been bad for so long. Searching title and description should be the standard way, people shouldn't have to cram stuff into a title to get their listing found. A good ranking algorithm, smart tokenisation, normalising, and stemming -  good full text search isn't that hard, there are solutions out there.  Doesn't matter if it returns a thousand, ten thousand, a million results as long as the ranking makes the first 20 are the ones you were actually looking for.  

My post has gone to pending beecause of the link, here it is screenshotted.