I wonder whether it's a Mac-specific issue. Is there a keyboard combination or long press way to "right-click" that works on bookmarks?

You can check for problems with the places.sqlite database file in the Firefox Profile Folder.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

In the Show All Bookmarks dialog, you should be able to use the form at the bottom of the right pane to edit the name of the selected bookmark, and the Organize menu to delete the selected bookmark.

(But... this comment is based on Windows.)

@cor-el That file (places.sqlite) is not locked, i Clean-Installed OS X a few days ago and then downloaded the Firefox 18.0.1 and Clean-Installed it too i don't think files are damaged or locked i tried those solutions anyway

@jscher2000 Yea that works, i'm already doing that, but its really annoying if you want to rename or delete a bookmark you have to open bookmarks library and then find the bookmark there, then delete or rename it, i find the dragging way a little faster

I don't think this is going to be fixed soon, so im looking for a way to rename and delete bookmarks in Bookmarks Toolbar

I think many have this problem too i have also created a topic here: https://bugzilla.mozilla.org/show_bug.cgi?id=834870