I went projectile/explosive, so I never used the energy beams, nor did I use the flame weapons. My friends went melee, so I could stand in the back, or so we thought. Then I got the level two weapons for both of my areas, and they're a little too short, but I started really mopping up on the experience. As of right now, I'm only level 9, on about the sixth stage, maybe. I haven't payed attention to the story.
Is the Quantum Ripper a gun? I haven't gotten that far yet. I think the best way to tech might be to use those leveling-up-like machines. Whatever they're called, you can earn proficiency points, and I think if you start a new game and import your character back and forth, you can use those to your advantage.