Corrosive Grenade: Speced into lethality tree...slowly ticking dot
Plasma Probe: 31 points required in engineering tree
Death Field: Speced into madness tree
Chain Lightning: Lightning tree
Wither: 31 points required in darkness tree
Smash: You are telling me a spec that focuses on aoe damage is better than fusion missile? That sounds ridiculous
Honestly you can't compare fusion missile with attacks that take skill points to get and a skill tree that revolves around AoE damage.
Although I do agree a slightly lowered heat cost would be fantastic.