#2 Nov 18, 2015 07:29
"Home / Main" collections are meant to host the home page of your site (http://b2evolution.net/man/collection-type-panel). They are set to display the Special Front Page display (disp=front). Also for generic functions such as messaging, user profiles, etc.
New skins as "Horizon" are often delivered in two packages (or more). One for regular "Blog" collections and another for that special "Home / Main" collection.
Do i get this right: it would mean to set up a site with two collections, intropage with Mail skin and then a blog with blog skin and the blog would be a subdirectory to the first one then?
Yes, you do get it right. If you want a home page design, you need at least two collections in your site, but there is no need to create one of them in a subfolder.
b) is there a way to keep the sidebar in the 'Single post page'-mode with the Horizon blog skin? I don't want loose the sidebar/menue and wonder if there's a switch to keep it.
This skin doesn't implement sidebars for single disp. You can apply this workaround to get it in your site: https://github.com/mgsolipa/b2evolution/commit/e5716a0b557d2bfae02873f8898a53a0b68c0b9c