How do I get back the green flashing arrow when downloading
Delete the localstore.rdf file in the profile folder.
for more info refer to: http://kb.mozillazine.org/Corrupt_localstore.rdf
Do you still have the Navigation Toolbar visible?
Make sure that toolbars like the "Navigation Toolbar" and the "Bookmarks Toolbar" are visible.
Use Toolbar Layout (Customize) to open the Customize window and set which toolbar items to display.