Hello,
Thanks for using our theme.
Please submit different questions via separate topics.
1/ Go to Theme Options > Speed optimization > Menu Cache, Static Blocks Cache, Remove Query Strings From Theme Static Resources > Off.
2/ Theme Options > Header Builder > Mobile > Top header >WCAG Background Control https://prnt.sc/-81Qw3i0cI_D
3/ We’ve checked and the sticky header works fine. What devices and browsers do you use?
4-6/ Here is the detailed article on the XStore AMP plugin you can read: https://xstore.helpscoutdocs.com/article/111-general-info-amp
You will find all the settings of the XStore AMP plugin under XStore > AMP XStore.
So please read the doc and check the possible plugin settings, Other than that there are no additional settings.
Regards