Hi,
HikaShop store order modifications in the "order history".
In the future, with the integration of the order edition from HikaMarket ; more precise data will be stored in that log which allow to have a log of the modifications.
About the product, there is no log for the moment but that's something we have in our TODO list ; specially for HikaMarket which need a more advanced approval system and want to be able to list the modified elements to let the administrator approve them or not.
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.