Use Fancybox :
if you switch off Fancybox, vmukit popup will be work. else fancybox will work.
Using the VirtueMart CSS :
you can disable this. because we are using youtheme css in all pages.
Using the VirtueMart jQuery Or Use external google jQuery library :
VirtueMart need atleast one jquery to work in Frond end. if you load Jquery from other extension, you can disable VirtueMart jquery. otherwise you muse enable virtualmart jquery. Jquery version must be equal or greater than 1.8. VirtueMart using Jquery 1.8 as default.
Using the product Scripts :
you need to enable this.
Using the Script ajax Countries / Regions Or Use jQuery chosen for dropdowns in FE :
you can disable or enable per your requirement. vmuikit works in both options.