1. I was planning to add a 2 before I left to go eat.
2. Thanks for pointing that out, but all I would have to do is replace it with anything else that doesn't use a gravity feed and it's fine.
3. Yes, it is easy to shoot something at those speeds if you're going at roughly the same speed. When a space shuttle (Endeavour) is in orbit it goes 17,321 miles per hour. An ICBM (Minuteman III) goes roughly 15,000 miles per hour. That would have to be sped up for a trip to Selene.
4. Again, it'd take your ICBM three days to get to Selene, and my nuclear propulsion system (Which was developed DURING THE 1950's on Earth and would have gone into space if it wasn't for nuclear treaties) could get there in roughly 3 hours during cruising speed (again, developed during the 1950's, not future tech). And on that nuclear propulsion ship could be, say, a missile defense battery.