hello, thank you for providing the crash id - apparently you have trusteer report (or lastpass) installed on your computer which is triggering the crashes.

please try to stop trusteerreport by going to System Preferences -> Other -> Rapport -> Stop Rapport or remove the program and see if the crashes at startup continue.

It worked! Amazing! Dare I turn on Rapport again?

hello - firefox will probably crash again right away. it's trusteer report causing the crash - apparently when the lastpass addon is present. please try to contact trusteer support at http://www.trusteer.com/support/report-problem (although due to the high number of recent crashes they should be already aware of the problem) and/or look out for any updates of the program.