Hello,
1/ Fixed. please clear cache and check now.
2/ Dropdown menus are aligned center according to the parent Main menu item, it is predefined behavior.
3/ Great.
4/ Add the next code in Theme Options > Theme Custom CSS:
#dokan-primary {
width: 100%;
left: 0;
right: 0;
}
#dokan-primary ~ .sidebar {
display: none;
}
Regards