User Activity

Is it okay to sell a lost item, for example, it fell out of a truck, or you found it lying on the footpath, and you don't know who it belongs to, does that count as the item being stolen, and therefore cannot be listed?
I am just wondering if it is against eBays policies to request additional funds (money) through Paypal or other payment method after a bidding session or buying process is complete. I have looked through eBays policy pages, but I could not find any m...