With missle strike you need TLAM's (land attack Tomahawk), not Harpoons. You need to launch them into the red circle on the map. It's the entry point for the guidance system. After last update once all 8 missles reach that circle the mission is counted as "complete" even if those tomahawks will later crash into the ground (they still have problems with terrain avidance
)
2nd one? Bad luck indeed. In fact i hate those seal missions: all the map there and back with only 4 torps? :/