Randomert Your modules could be better, especially the cannon ones. Try to split them up in more compact smaller ones.
I think you're using too much prisms. I'm experimenting with things like this, but I'm not really sure if it's the best solution on your ship.
This way your beams pass through less prisms, enabling you to have money for extra reactors to power the beams endlessly. It's also good to note that the beams pass through the structures without problem.