The shuttle is very good. I killed a few destroyers and carriers with it in my first playthrough, and stuck to it for a pretty long time. You have long range weapons and are pretty fast, so blowing up larger, slower ships is actually not that hard. You probably will not get a cruiser because those have enough flux reduction to never have a problem, but destroyers a pretty easy. Just shoot them at max range with the IR lasers, have shields up, vent flux after a missile barrage hit your shields and back up a bit, continue until the destroyer is dead.