I played GalCiv back in the days of OS/2, and I never questioned the physics of open map, these are games after all.
Once I decided in GalCiv not to be aggressive at all, just to stay in my home system and see what would happen. Picketing a ship/satellite on every square became a little annoying.
So that's a vote for warp point/jumpgate/hyperspace jump points. When you think about it, all sci fi uses warp points, in a way. Nothing ever happens to the Enterprise while its at full warp, Vader can't catch the Millennium Falcon while its in hyperspace, etc.
Pretty well summarized, right here.
Schlock{clicky}