Point defense would be used against fighters, bombers, missiles, and if they are detected before they come into range, ballistic weaponry such as high-density rounds and the like.

Lasers would be most efficient in space for use as point defense: more powerful lasers would be powerful, but would be stressful on energy because of its energy-guzzling properties, even for the CI's fusion reactors, which are the best energy reactors known. I say this because these fusion reactors have to keep these shuttles going for millions of kilometers without breaking down, sputtering, or the smallest malfunction, and they are powering countless systems, including life support.

Larger weapons would be used against larger targets. Right now, a place such as Ceres, a fortified dug-in position that is inside a landmass of some kind would require very, very powerful weapons. As in 20 megaton nuclear warheads or greater to just start scratching the surface. If there are space battles, it won't be decided by how many large ships, but rather how many small ones. Fighters and bombers would be instrumental, because they are easier to man and build, and they can attack with more accuracy. Missiles and light energy weapons could be attached, and would make someone having carriers and the other not be the deciding factor in a battle.