Bill,

most scouting vehicles are very lightly armoured and armed. Agility and warning are the key goals. If you shoot up a boat like that, you will attract notice and a response, and that is probably the whole idea. For the rest, I would not know.
I definately would not like any autonomous vehicle around me except for the kind running on tracks. At least for now.
The USA (and probably others) are developing armed autonomous "robots", and that is really, really, scary in so many ways.

Pete,

I think we will see more sail and sail assisted in the future. Shipping is very economical compared to air, truck or train freight, but they are always looking to save money there as well. At this time bunker oil is still cheap enough to make sails a future development avenue.