Hi,
We have an CSV import function as well in HikaShop:
www.hikashop.com/en/support/documentatio...hikashop-import.html
So if you can export your products information from VM you should be able to import them in HikaShop after adapting a bit the CSV. There is no one click button to import all the information in VM into HikaShop, at least for now.
There is no automatic way to handle sales reports on the front end. HikaShop does not support multi vendor for now anyway.
In the Business edition of HikaShop, you have an option to change the group of a user after he buys a product. That way, you can handle the access to other areas of the website.
You can have discounts and in the Business edition, you can restrict discounts to user groups.
You can have downloadable products in HikaShop. In the config of HikaShop under the tab files, you can change the folder of the files (and images as well). Then, on your server you could create a virtual folder there which would be a network resource for example. But you can't put a link from another server directly as a downloadable file.
You can create directly slideshows from products in HikaShop. However, you can use any slideshow component available for joomla and include your product images and links to the corresponding products to achieve the same.