I'd absolutely love the Clanbuster if it would drop that Hatchet for another standard Large Laser. I've never liked physical attacks, even if a 15 point is nothing to sneeze at. With three LLs, you can still engage with the ERPPC and two of the LLs at range without overheating significantly, and as soon as the range drops to ten hexes, you've got three LLs and a LPL to lay into the opponent.
Although, playing around with the design, I think my favorite thing to do would be rip out everything larger than two tons and replace them with large lasers, max the armor, add a heatsink, and fill the last two tons with a fifth MPL. Turns it into a withering energy boat of death. Five LLs isn't anything to sneeze at, especially if firing all five of them only puts up 8+ on the heat scale, which is a fairly manageable heat spike for putting 40 damage down range.