Hi,
You can no send the content of the cart, there is an option in the paypal plugin for that.
After that if you want to remove the product code, you have to edit the paypal plugin and it's not really recommended if you want to update your HikaShop (because you will loose your modifications with updates).
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.