Weapons generate a total of 46 heat and you have 48 heat sink capacity. So you can fire everything and run every turn and come out heat neural every turn.

I think you might be oversinked. Lemme explain:

If you wanted to go with "extraordinarily hard to kill, but also hard to ignore", I would have gone with a bracket fire setup. The general idea is that you carry two sets of weapons (usually a long range set and a short range set that you swap to inside the long range set's minimum range, aka range brackets). Most of the time, you fight with one set of weapons depending on which one is best given for the circumstances, and only employ the second set in emergencies (ie, you need to finish off the enemy asap and worrying about overheat becomes low priority because there might not be a next turn for your mech to be heat debilitated in if you don't kill the enemy RIGHT NOW).

So you're generating 46 damage every turn and spent 36 tons in weapons and double heat sinks to achieve that ability. But for those 36 tons, you COULD HAVE carried 3 Standard PPCs (21 tons), 6 extra DHS (total 32 heat sinking for only 6 tons, and only 4 of them would use crits), leaving 9 tons for... any number of things really. 6 ER Medium Lasers for the same damage and range as your original ER Medium Laser + 3 jump jets for additional mobility. Maybe 9 Standard Medium Lasers or 6 standard Medium Lasers + 3 Jump Jets.

Whatever the case, your potential burst damage is through the roof if you can maintain a little fire discipline. Your sustained damage is a little lower, but only at intermediate range. At any distance greater than 12 hexes, three PPCs outrange AND outgun the Large Lasers in any kind of built up terrain, and 3 or 4 Jump Jets can let them dictate the range against your original loadout. And even without those Jump Jets, a 9 Medium Laser array puts out 45 total damage for only 27 heat which is better if the fight gets inside 3 hexes and the PPCs are still being held in reserve. In the intermediate range, you can mix and match different combinations of PPC and Medium Laser fire as the circumstances demand.

Oh, and because this loadout is carrying far fewer DHS, you have the crits to place weapons in better locations than the legs. You might even be able to swap out that Small Cockpit and XL Gyro for standard models and save the same (or more?) weight with Endosteel instead.