Thanks for using our theme and for contacting us.
1/ Disable XStore AMP plugin
2/ About the header, that demo uses multiple headers and a separate header for the home page. Please, watch the video tutorial on how to edit the multiple headers https://youtu.be/BpeXfzNwkOc Let us know if you have any issues after that.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.