I'm with you on the importance of space exploration! I think the most important effect is your number 3, tech innovation and the way it trickles down. Especially if we colonize the Moon or Mars, we will be forced to invent new technologies and improve our existing methods of things like water reclamation and food production. A game I play called, Surviving Mars, says, for example, "GMO crops gain much popularity when the only other option is red dirt".