To answer the seller about a bad return. I do case by case. If the buyer is a new guy with no prior record I tend to side with the seller.

Let's say we do 10 sales and 9 are good the 10th is a return and it is legit.

This would show me you are a good seller.

So sale 11 happens the buyer returns a gutted laptop.

I am going to side with you the seller.

Let's say you do 10 sales and four people say the gear was bad. And I happen to know a few of the people from prior business or escrow most likely I will side with them.

Once you do enough good sales most people would no longer want escrow and you can then trade freely like I do .

Getting started as a seller here takes 5-10 good deals a few trust points from good sale etc.

If you get a buyer that wants gear from you send me a pm.  As to who pays the escrow more often then not the buyer pays the escrow fee.
I can say at this point in time every escrow I did either ended in a good sale or a good return.