The Easiest way to deal with the preposition base issue is to make the mission be "to a secret base location within (Fill in the region)". After the mission you get to place the base within that region. You make the first day of the game be one of these missions to get your first base placed. You only get one "mission" for a free base in a region per game, timing on when could be based on relations and how well you are doing etc. Otherwise to place a base in aregion you need some sort of "good" relations withthem so they will "seel/lease" a base to you.