Your mech has a couple of flaws. First of all, God Mode legs + Rocket Launchers = blind spot after you stomp twice. And any melee or lava user will abuse this blind spot, so your only option is to teleport away or move back, and that means one action point wasted for no damage. Another thing is, I always add a resistance module to God Mode torso, because -24 is way too much. Also, heat mechs do worst against Diamond Shell (I know what I say, I run 2xDS myself). Much better options against DS is physical or energy mech. Energy mech is also excellent against Lava Spray, since you need 7 energy to fire LS. To sum up, I would forget heat and switch to physical or energy.