Excellent add-on! Rated 5 out of 5 stars
It makes significantly more then described!
1. It opens ANY shortcut bookmark, not only for search in new tab
Therefore I have 2 suggestions:
1. It is better that item "Keywords Bookmarks" will appear in context menu anyway, not only if some word/phrase is selected
Let say, left click - in new tab, right - in the same and middle - in the sidebar