Incendiary is good when coupled with a quick firing or hard hitting weapon, for quick time to kill. The reactive reload is pretty good coupled with trance and chain, but scavenger will help getting back knifes and grenades. Personally, id go scavenger, especially with hand vannons, but thats up to you. I would also suggest combustion, but if you want quicker cooldown, thats fine, but combustion can kill groups and more enemies then gunslinger. rescue mag on split shifter isnt going to do much, if you have a different secondary with better perks, i would go with that. Heavy would have to be a machine gun, quillims or thunderlord are great