The the7 theme allows you to control archive layout by selecting a page in Theme options > Archive but there is no option if you want to assign different archive templates for categories. for eg News archive want a list layout and Event archive to want to display in masonry grid. This can be done
Header layouts in The7 theme is global, there is no option to change it on a page wise. When you use Microsite template, you can hide/show header, select a different menu, logo etc, still no option to change header layout etc. This can be achieved by changing The7 config values using hooks.