Documentation: additional themes and its performance including
Documentation: create block and its settings: content, theme, ...
Documentation: install, update and setup WP Latest Posts
Documentation: add blocks on Editors and widget loading
Each WP Latest post block can be called in editor (page, post, custom post type) or as a widget.
Yes you can! Each theme have it's own css loaded separately.
Yes it is.
You have a default theme included in the free and pro version where you can set elements (title, text, read more, author, date) in 4 position on a grid. You can do that using drag'n drop.