I don't know if it's possible, but I think it would be great to add a fuel mechanism to the game. This would restrict how far you're able to travel outside of your known universe. You would be unable to just fly scouts througout the galaxy and find the opponents ASAP. Then new research items could be introduced that reduce fuel consumption for frigs, cruisers, and capital ships. Perhaps a refueling station that can be placed in any planet system (not requiring you to own it) that allows you to refuel your ship over a duration and cost. New behaviours could be introduced that allow you to tell a ship to auto return to a base once only 25% of fuel is left. New cruisers could be created that are mobile refueling stations that have 2 supplies of fuel, one for itself, and one for others.