eBay Unfair to sellers Internet

I feel they are unfair to sellers heres why one they have a 30 day returns how unfair to sellers that is if a buyer buys from seller an item they could potentially use it 29 of them days and file a return after they use the snot out of it and make false claim that it wasnt as described the seller gets a defect on their account after 3 you get on back pages of search and lose sales thenext thing is connected to this the seller has to refund evey penny to buyer including the original shipping so seller loses that much more by more meaning the investmet into item and extra to replace original shipping and they expect sell to also pay return shipping as well heres a example of what I am saying seller say pays 20 for item ok sells it for 40 plus say 7 shipping charge buyer buys pays 47 the item is used heavely day 29 return is requested so when seller get it back it unsellable ebay want you to refund the 47 the 40 is ok but the 7 the original shipping shouldnt be part of it its gone used up I feel so seller gives back refund so seller is out 7 then stuck with a 7 for retun lable that 20 seller paid now is 34 plus seller is out the item cant relist it that I feel is unfair policy ok next unfair thing is they did away with sellers givinf negative feedback yet buyers can leave it the buyer could say the seller is no good and dont but from them and other potential buys can see that and may skip a good deal and seller loses out. to add to the returns part if selle disputes a defect or buyers claims ebay will still side with buyer and I asked why one time they say they dont have items in their hands and cant determine how it was sent so basiclly if you sell on ebay its a gample