Just for testing purposes I set up a clean Joomla 3.3.6 site with only VM 3.0.
Some things I encountered with translations:
I made one product:
(http://yndidev.tk//vm3/images/vmtest/Yndi%2020141120%20-%201103.png)
I opened the product:
(http://yndidev.tk//vm3/images/vmtest/Yndi%2020141120%20-%201104.png)
Switched to English language and translated:
(http://yndidev.tk//vm3/images/vmtest/Yndi%2020141120%20-%201105.png)
Switched to Dutch language: image flag is English flag. Translation is ok, but flag is not:
(http://yndidev.tk//vm3/images/vmtest/Yndi%2020141120%20-%201106.png)
I suppose something goes wrong here:
(http://yndidev.tk//vm3/images/vmtest/Yndi%2020141120%20-%201108.png)
Double slash is just a "cosmetic" issue I suppose, but I think css definition is not ok/constructed in the right way.
Shipment method translations works with flags as expected BTW:
(http://yndidev.tk//vm3/images/vmtest/Yndi%2020141120%20-%201110.png)
Furthermore article descriptions and category descriptions can't be translated.
Thank you very much for the detailled bug report.
One problem was only in joomla 3 due tinyMce 4, the other was always. Is fixed in the new version, then. Thank you.