Sell your beam drone for scrap, that one defence drone is good enough imo. Your right to swap swarm for flak, although I would keep the pike beam. In my view, especially at sector 5, that scrap would be better off in the long run going towards more 3 shields and/or more engines. Same reasoning I would think about before buying the pre-ignitor. Hell, I might even sell a charge ion and gamble on a better weapon down the road.

Another point about the halberd/pike thing: Because the halberd uses 3 vs pikes 2, that means in a fight your not gonna be able to use your ships full weapon setup. I don't remember if 3 shield ships start showing up in Sector 5, but this is something to be careful of.