Hello,
The vendor page can display various information thanks to "vendor custom fields".
You can also display HikaShop modules in that vendor page, which allows you to have a product listing, or else.
Displaying the number of products the vendor own or the number of sales is something possible but it may need to use a view override in order to retrieve the information and display it in the page.
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.