I do buy some groceries on Amazon.  They have a decent selection of gluten free foods there that end up costing me less than if I were to buy it at the grocery store.  There is also quite a few regular pantry items that were around the same cost as the grocery store if you subscribed to them AND the shipping is free.

There is also a site that sells organic produce in the upper midwest area that is cheaper than the farmers markets and co-ops.  (They sell organic apples for 50 cents per pound, $2.00 for a dozen organic free range eggs, etc.)  There aren't shipping costs, but you do have to go pick it up.

I have a fairly large list of non paying bidders from the past few months.  I'm not sure what it is - but I have noticed that people who purchase "buy it now" items tend to pay more often than people who bid on the items.     I do have automatic selling blocks to block people who have 3 strikes within a 6 month period, and it does help a little.

Another trend I have noticed are people who fail to understand how eBay works.  I had a woman buy something (non pony) and pay with an e-check.  I shipped within 12 hours of her payment clearing, but she gave me a negative as she expected me to ship as soon as she completed check-out.  Years back, it seemed as though it was common knowledge that most sellers waited for e-checks to clear before sending items. 

I don't think I can add any additional reasons that haven't already been mentioned here.  I haven't really had issues with things disappearing, but I've sent several packages that have taken forever to arrive.  Luckily, most of the buyers are aware of customs delays - but not all of them are.  It helps if you tell your buyer upfront that it may take several weeks for their item to arrive.

My brother moved to Australia last summer and had me mail some of his belongings to him.  Around 8 of the boxes I mailed were Priority flat rate, around the same weight and mailed at the exact same time.  They all contained books.  The address was printed out on the computer - so they looked identical.  He didn't receive any of them on the same day.  The first ones showed up to his door in 2 weeks and the last one took 8 weeks to arrive.

I know that NZ and Australia aren't the same place - but I am noticing that nearly ALL international packages are taking their sweet old time lately.  (I even just lost my 100% feedback score because of it on eBay.) 

As for a small mistake in the address - it may cause a delay, but the package should still get there.  It doesn't sound like it was totally botched.   

It is SO rare for a package to go missing forever.  I've mailed out thousands and it's only happened a couple times.  * knocks on wood * 

I'm not sure what it is about female rats.  Every single one (literally) that I've ever had eventually ended up with a tumor - usually between the ages of 2 - 3 years old.  It didn't matter what diet they had, the size of their cage, etc.  I can understand not having surgery done on her.  The two times that I took them to the vet, they died.  (I haven't had any though for almost 2 years though, although I don't think that the procedures changed all that much.)  If you do decide to take her to the vet, see if you can find one that has experience with small animals. 

I'm sorry about your little pet though.  Even if they're small, it's still tough to see them hurt.