Everything is OK, it won't hurt your pump to run constantly while using water through a hose. With a 1/3 hp shallow lift (1 pipe suction) I'm not surprised that the pressure drops to 25#. If the pump cut off before but does not now I suspect that the water table has dropped enough disallowing the pump to build pressure enough to pump to the pump cutoff setting of the pressure switch. I suggest that you lower the cutoff pressure to a lower pressure. To do this, while the pump is running with the water outlet (hose) off, turn the long screw on the pressure switch counter clockwise slowly until the pump cuts off automatically. Now the pump will come on when you use water and it will cut off automatically shortly after you stop using water.
ALSO: I suspect by your description (and age of the system) your pressure tank is a non bladder tank. Also since it was only used for irrigation I doubt that it had an air volume control on the pump. Therefore by your description I doubt if there is a schrader valve (tire valve) on the tank to remove the excess water from the tank. RECOMMENDATION: If there is a 1-1/2" pipe plug 2/3 way from the bottom and on the side of the tank, remove the plug and replace it with a 1-1/2" by 1/4' pipe bushing and install a schrader valve (tire valve). Unplug the pump, drain off all water, then with an air tank or portable air compressor add air to the schrader valve until all water is expelled through the open garden hose. Once air comes out the hose, turn off the garden hose, turn on the pump and it will build air pressure in the top of the tank. This will last for months befor needing to do it again.
