there appears to be a lot of dead weight. For example, if you have vertical lift engines powerful enough to hover, why do you need those 3 big engines in the rear? Use lift engines powerful enough to land, hover, and take off. It appears the structure is somewhat overbuilt for lunar G loads, too. There is no need for streamlining in the crew compartment and the lightest shape for a pressurized module would be a sphere. A sphere not only offers the greatest amount of internal volume for a given surface area (better for thermal control and skin weight), the internal pressure will try to distort any other shape to a sphere.

Personally, I visualize something similar in format to the Sikorsky CH-54 Flying Crane helicopter. You'd have a small crew compartment in front with the engines mounted in such a way as to allow suspending payloads under the backbone. I'd want the engines to be mounted in such a way that attitude control thrusters would allow you to maintain control if one engine failed. That means they'd need to be close together. You might have to jettison the payload but you'd be able to save the crew either by aborting to orbit or making a safe landing. The vehicle would be built as light as simple as possible with nothing thrown away. Refuel it, preflight it, and fly. The initial version might use hypergolic engines but, if harvestable lunar resources are found, they could be replaced with methane or LH/LOX engines. Design it to carry a substancial mass from lunar orbit to the surface (say 15-20 metric tons), land, drop the load, and have enough fuel to fly back to orbit.