Hello,
1/ You can change 46px font-size to 5vh
or
add this code in Custom css for page:
h2.vc_custom_heading {
word-wrap: break-word;
}
2/ Theme Options > Shop > Shop page Layout > Sidebar position for mobile.
3/ Please read this topic https://www.8theme.com/topic/website-running-extreamly-slowly/
Regards