For me, they don't scamper, but get destroyed, and after that the rest decide to pull out. I have no problem dealing with Tie/A. It's actually that damned shuttle which always costs me the mission, or more precisely, the mines between me and him. I know it's just a bonus objective, but I need to do it. It's a completionist thing. I tried destroying the tugs laying mines, but get vaporized by Ties in the process. It's something you have to do early or not at all, so there is no time to mess with starfighters.

As for missiles, no matter how you turn it, you will get into a dogfight. From what I gathered, you just have to be quick. Fire those missiles from afar, get in close, cut your speed to 2/3 - for better turn rate - and pump your shields. All this is easier said than done because those damn Advanced are worse than A-wings when it comes to hitting them.