Discuss 'per folder' feature

[ghisler(Author)]

Will it be possible to set reversed sorting?

Yes.

"Branch view" or "Search results feed to list box" is a folder type

Search results: Yes.
Branch view: Not so far.

What does 'directory' mean - how are subdirectories managed?

You can choose to include subdirectories or not. You can combine multiple rules with AND/OR to exclude certain subdirectories.