"...buy genuine high quality parts from Digikey, not from "a seller" who gets junk from China." ... Exactly. Just because the eBay says US seller, doesn't mean that the part he is selling is from the US.
Solder flux will help, but the rosin core should be doing that for you.
Also you could seat a dummy IC in the socket while you are soldering to help dissipate some of the heat and keep the pins from coming out and the plastic case from melting.
Lastly, it sounds like your soldering iron could be too big or the temperature is set too high.