Bob,
I had a Harbor Freight 2" pump that I put over 200 hours on and it was still going strong. The only problem with it was that the engine was oversized for the pump so it used too much gas. Sold that one and bought a 2" Honda that uses about half the gas and pumps a little more water per hour.

Yes, it will pump 400 feet. The volume will depend on TOTAL lift plus distance. If you are pumping 50 feet high over a hill, then the pipe goes downhill 25 feet, then the total lift is 25 feet.

I am getting about 3,800 GPH with a total lift of 16 feet and 490 feet of pipe. The slicker the pipe, the more volume you will get. I have some poly pipe with UHMW liner. It's very slick inside.