Number 1.
A controller can clear a flight to destination via "flight planned route" even though an oceanic clearance has not yet been obtained. It is still the pilot's responsibility to obtain and adhere to that clearance whether or not it is the same as his original flight plan.
As an aside:
Our flight planning computer will show the Clearance Controller whether or not the route has been modified from what was filed and will require a readback of the modification.
Also if multiple FPLs are filed without cancelling the previous ones, the controller will check with flight planning and may be required to confirm the entire route if it cannot be determined which one the crew intends to use.
I had to read and obtain a readback of the entire route from CYYZ to UKBB with Aero Svit the other day for just this reason. Pilot was not impressed because the route I read was the same as the one he was expecting but he read it back verbatim and quickly.
