What happens to queries that are executing when SSMS crashes?
When SSMS closes for whatever reason, your session will end and any uncommitted transactions will be rolled back (and yup, database restores will stop).

BUT, if SSMS crashes and gives you the 'This Program Has Terminated Unexpectedly' or whatever the error message is, don't touch anything.  At this point you might find that your session is still active and will be until you click 'Close' or 'Restart'.  

I've had this a few times but if you open up another instance of SSMS and run sp_who2 you'll be able to see if your transaction is still active.