Hi,
1. The issue is that you turned on the "use bootstrap design" setting of the Hikashop configuration but it is only compatible with boostrap 2 while your template is only compatible with bootstrap 3.
Turn off that option, or apply this to have HikaShop support bootstrap 3 and that will solve the problem:
www.joostrap.com/support/tutorials-video...p3-super-easy-update
2. I don't know why this happens. It looks like a problem with the template. Could you try to switch to the default template of Joomla and see if you see the product page with it ? If so, I would recommend to contact your template provider. Otherwise, I guess we would have to check your website settings.