If you post from the account you're asking about, you will receive better advice.
Sellers get way too worked up about returns. They are not that big of a deal, and definitely not worth losing sleep over.
The Buyer has to upload a photograph when they open an IND Case, so you can check the Item there. There is no use trying to fight an IND Return. Personally I would not refund/part refund without a case being opened. Also I assume the Buyer is honest until proven otherwise (again for peace of mind, and to save valuable time).
If something had something with a high rate of returns, I would double-check that Item is worth selling on eBay. Then I would ask: Can I improve my photos/description? I would also consider sealing the item with clear size/model on it. If a Buyer returns an opened/unsealed item you then have an easy to explain reason to refunding as little as 50%. At least on eBay UK they still protect Business Sellers' Feedback in these instances!