Check to see that your halyard is not wrapping up around the headstay. If the halyard exit is not angled away from the headstay it can wrap easily if there is a high amount of load on the swivel (like when you are in windy conditions). Also, backstay should be tight enough so that the sag of the headstay is somewhat minimized; if the headstay is loose then the foil will not want to bend as it rotates around the headstay.
If your halyard goes to the top of the mast and it exits the mast more than 8-10" you should add a pennant made of stainless wire between the head of the sail and the swivel. That will minimize the ability of the halyard to wrap up because the eye splice is thicker and it won't twist as easily; and the length is shorter between the swivel and the sheave box. When I added a pennant to the head of my jib
it eliminated the problem of a wrapping halyard.
Also make sure that the furling
is running free and be sure that when the line
exits the drum it is at 90 deg to the headstay because if it is not the line
won't spool onto the drum evenly. You should always have about 10 extra turns on the furling
drum so that you don't run out of purchase if the sail furls tightly around the foil; so you should either add more turns by dropping the sail and then pre feeding some in by rotating the drum by hand, and if the line
is not long enough for this replace the line with a longer one.
Another thing to consider in the situation you were in is that it is nearly always safer to remain under (reduced) sail than to try and drop sails and motor to your destination. I agree that you had a tough situation with inexperienced crew and double-handed; but even if you reduce the headsail to a storm jib
size and then either spill your main a bit or reef it (I know this might not have been an easy procedure given your scenario), you are going to make better time and in more safety than under motor alone. I think of my engine as a device to use in an emergency; since it is also difficult to raise sail if you lose engine power while under motor alone (if your filters get clogged, or if you have some other engine related failure). With the situation of tacking into the wind with waves on the beam; just spill your sails a bit; go at the waves on with them aft of your beam a bit and you should be OK because your heel will be reduced and the wave will push your stern to windward. If you see a big roller coming you can round up and let it go past your bow then continue along. Morgan 416 O/I should be up to the task; next time you head out into challenging wind conditions be sure and have more crew along.