XF 1.5 Limit "New posts" (sidebar) to specific category / node


Well-known member
I'm searching like hell in ACP options and here in forums. It must have been asked 100x times already, but I seem to be blind:

1.) How do I limit the "New posts" from sidebar to one specific node, please? I found "Node & Forum List" in options, but there is just the amount of new threads...
2.) Where / in which template I would have to look for the title for the "New posts" sidebar panel? I would like to link it to the same catagory as in no. 1.). It's not "sidebar_new_posts" I would think, that's just the list of the new posts.

Thank you for your patient help to these noob questions. I am just overwhelmed during finalizing the vb migration.