Yes, you can return them for exchange or credit on most purchases, but there is a time limit to that, and if I recall right, it is within 24 hours of receiving the merchandise.

Of course.  Just tell the seller and he will tell you the return address.  Some might be reluctant to return and try and persuade you to exchange but if you want to return things you can. 

 Theres no time limit, just make sure that you tell the seller and then if it trys to automatically take your funds you can tell the seller and he will extend the automatic deadline, but I think thats 14 days or something, enough time for the product to be sent to you and for you to send it back,

Rearia, you're not suppose to pay taobao until you have looked over the goods, after that you have the ability to send the money or send the product back. I've never had a problem with sending something back for exchange but have had some problems with refunds if I wait more than two or three days to respond to their QQ about liking or disliking the product

Yes you can. When you buy an item, be sure to look for the return sign from the buyer. Its a small picture of two hands with either a 7 or a yellow box

yes you can 

definitively, though it is somehow complicated as they always like profit and not loses. ,this depend on the contract with your seller, an item have a specific time during which you can return to it in case you encounter an error, but after that time is over you can only change to a new one or something similar that is if they happen to have such in their store.

Yes!

yes you can..some stores on taobao di have this choice..before buying you can see some signs beside the shop items....one is return in a week..the other is if the product is fake they will pay you back twice what you paid and the third one am not sure about it maybe it has something to do with express delivery in a day or two....just check the signs that appears with the product and you will know what they store offers you......God Luck adn please don't get cheated on taobao