How will people be able to transfer PING they buy from Cryptopia to use your service? Also have your talked to coinmarketcap.com
Haven't talked to Coinmarketcap yet, that's on the list after Cryptopia market is open. When subs go live we will add deposit interface on our website for PING so it can be transferred to us.
Also can I just withdraw to the Waves wallet on Bittrex?
No, you cannot, because PING does not equal WAVES. They are separate, different crypto assets, but simply put PING token works on Waves Platform technology. Please read more about Waves Platform on their
website.
... can i sent the Coins latter from Waves to other exchanges , like cryptopia etc..?
If you have withdrawn your tokens to a Waves wallet, then you'll certainly be able to transfer them to anywhere you want, including exchanges.