Rated 4 out of 5 stars

1) Can I see all-notes list - for example, if I forget to what message note attached?

2) Can I make note to folder?

ad 1) Notes are stored in the "XNote" directory under the Thunderbird profile directory (http://kb.mozillazine.org/Profile_folder_-_Thunderbird) - unless you changed it. You can open the files with any text editor.

ad 2) No, because notes are tied to a mail's message identifier.

Rated 5 out of 5 stars

Can I add note to folder?

Rated 4 out of 5 stars

It cannot see path to store in UTF-8.
In Russian it create path for example "Рабочая" (in options I wrote good path).

This review is for a previous version of the add-on (2.2.7). 

Fixed in version 2.2.8

Please try it.