Agree for no FTL travel. Just adding feature of our system solar around Kerbol... Asteroid belt, comets, asteroid to destroy because they too close from Kerbin.... Icy moons like Europa, somewhere we can get trough the ice and where we can send submarines... Imagine lading on a moon like Io... volacanoes, io-quakes... Adding more dangers! There's a lot of thing that can be added before other star systems...