Hi,
Problem #1:
There are 2 different ways to solve this problem. Do, either one of them.
Method 1: Navigate to
VM backend >> Configuration >> Template and disable this option:
Use jQuery chosen for dropdowns in FE
Method 2: Open this CSS file:
ru-dacha.ru/templates/da3_51/html/com_virtuemart/assets/css/flexible.css
scroll to the very bottom and include this CSS rule:
.product-field.product-field-type-C .product-field-display { overflow: visible;}
You will be good to go.
Problem #2: This is a known bug. But displaying "Related Categories" is problematic with official Virtuemart Component as well. Related categories won't be displayed in appropriate ways (thumbnail + name of category). Hopefully this problem will be fixed in the upcoming Virtuemart release (vm3.0.14). If not; we will try to patch it in the upcoming CleanMart using our own ways. For now, it is what it is.
Regards.