An interesting concept might be to get rid of the integration of i18n from the product for certain aspects such as product description etc.. but instead to have module that automatically detects the languages installed in drupal and create a field for each language for each field type (description, product name, etc...)
Then maybe to have the fields visible based on language?

It's the beginning of an idea. What do you think?

I'm already imagining some complications but I don't think it's impossible. And it would avoid the multi-product problem for each translation... 1 node for as many languages as you like. And those fields can also be assign on node_import.