Thank you for your help with French language translation. I have informed our engineers about it. They will fix it as soon as possible.
If you find any other issues with translation, please, feel free to post them in our Bugtracker
Regarding attributes names and values, they has been set in for each product in Ecwid control panel → Catalog → Products → Product modify page → Options tab. As you can see you can add/modify/delete options as needed. This means that you can set names and values for options, as well as all other categories and products info on French language without our assistance.