I have the same problems with a fresh installation of joomla 3.4, virtuemart 3.0.6.2 and the epic pro template 6.0.8. No chance to put products in the shopping cart, not working buttons for plus and minus, the shopping cart is only an empty page etc.
The template did not work with the new virtuemart. When I deleted all virtuemart overrides of the template, the product pages works as expected.