It seems like 150' distance to the well, with a slight uphill slope from well to house would reduce your available pressure a little, but not much. I've heard of people with longer runs. Pumps typically can push water farther than they can suck it, which is an advantage of a submerged well. Your pump is basically pushing the water straight up the well, and then another 150' up to the house. That may be why the pump pressure is set at 70, to compensate for the run so that you would still have reasonable pressure in the house. Some of the other guys here know more about the pumps and tanks than I do, so they'll correct me if I'm wrong.

Keep us posted when you can check the tank output. I'm still guessing corroded lines. If your well is put together like mine, there is a plastic line buried 4' deep from well to house. After That, it's galvanzied and hard copper.