Hey it would be great if you had a way to assign an IPN url that I could integrate with paypal for premium users. That would be very helpful for moving some items.

Do you mean that using the bot to play the role of a middleman for paypal and steam item trade?

That won't be possible. That would mean that the money will be sent to us before sending it to the user. There is no way to automatically send paypal money (as far as I know of) and it won't help against chargeback either. We will only implement Bitcoin if we are really going to do something like this.