Just a couple of things.

First the thrust of a rocket engine is dependent upon two parameters. The flow out of the nozzle and the pressure force at the exit plane.

http://www.grc.nasa.gov/WWW/K-12/airplane/rockth.html

For the LM at landing, about half the thrust is the pressure force and half the force is due to the flow. So in reality the force on the lunar surface is around 1500 lbs. My over 2000 lbs car is in the parking lot right now and it is not creating any holes, ruts or whatever.

Second, the engine nozzle was about 54 inches in diameter or about 2300 square inches. Using the two numbers shows that the pressure is less than 1.0 psi.