I think there are answers to your questions.

There are a couple of reasons why your buyer could not make an offer,  they could have non payment strikes forbidding them to buy from you, and hardly likely to admit to that.  Or,  if you have a minimum that you will accept on offers,  this has to be exceeded not even matched for it to go through to you.

Refunding a customer does not solve the issue if they were upset about a certain aspect of the sale.  They were disappointed that the covers were faded, yes a refund was made,  but this does not take away the disappointment of the transaction,  so eBay would not remove the feedback. 

However,  did you try and explain why they were faded, perhaps then the buyer would accept a feedback revision from you?  If not,  luckily neutrals do not affect your seller feedback.

Sales are low for everyone. You have beautiful items for sale but in a market with Great competition.  I had a quick check of 3 of your lovely dresses and found the identical ones or very similar ones which are cheaper. 

Buyers have a ' Best Match >> Lowest price .  Buyers will always select the cheapest if identical / similar items are offered for less.

It's a harsh market for online clothes selling far more sellers now,  peeps it's true, with less money and tightening their belts all adding to what everyone is feeling hard times for selling clothing items.

@anytime-anywear