You missed a few things about the poor portrayal of space battles in the cinema:
- Orbital Dynamics - When space ships are near a large mass, their orbit matters. Suppose, for example, you have two space ships in the same orbit around a planet, with one 10 miles ahead of the other. If the ship to the rear points its nose towards the lead ship and accelerates, it will not start to move towards the other ship. It has just changed velocities, which changes its orbit, which changes everything. In this case, the ship would start to move to the outside (away from the planet, that is) of the other ship. Depending on the velocities involved, it might not even get closer to the other ship at all. This is why it takes several hours for the Space Shuttle to rendevous with the ISS - matching orbits is no seat-of-the-pants trick.
- Velocities - The velocities involved are enormous (about 5 miles per second for low earth orbit). How would one of the Star Wars battles look if Luke's ship was going 5 miles per second faster than the enemy. Hell, he'd hardly be able to see them.
- Sound - No air, so there isn't any. No explosions, no whoosh of passing ships, no sizzle of laser fire.
- Longitudinal orientation - even more insidious than 2D vs 3D is the problem that, unlike aircraft, space ships don't have to always be pointed along their velocity vector. The shuttle, for example, often flies butt-first along its orbit. The most effective way for a space ship to turn to the right is to turn to the right, then thrust. Real space ships will look almost nothing like aircraft when and if they ever take part in a space battle.
As for the last part, war is not always stupid. Where would we be now if we hadn't taken Hitler out fifty-some years ago? At some point, people probably thought that war would never make sense between countries on different continents, but we eventually proved them wrong. If we really move into space as a race, you can bet that war will move along with us.