just use the app Top Sites from store...You can't set it to read-only but you certainly can set the bookmarks view count to an extremely high value that won't allow them to be practically modified...


Edit: FYI the .db is located in /usr/share/grob/url_history.db which if you modify could potentially need to have its sha1sum value updated in the refhashlist... I think a few months ago there was a similar post by The Best Isaac in which IIRC he mentioned he as able to modify the .db file without having to update refhashlist...Search the forum for it...