Hi,
10K products shouldn't be a problem for HikaShop. We have users with a few million products and it starts to get problematic.
Regarding the import of the categories. I checked a bit the code and it seems that there is an issue with the VM import above a 100 categories.
Replace the file administrator/components/com_hikashop/helper/importvm.php by the one in the archive below and that should help avoid the issue (note that it might create duplicated categories if you do it over your previous import instead of on a clean HikaShop).
This attachment is hidden for guests.
Please log in or register to see it.