Need Pump Advice, Please

Can you break the line between the pump and filter? If you can, and then the pump runs and spews water all over the place at the line break, you may have a blockage after the pump (I wouldn't think that very likely though).

If you have to cut the line, you can easily glue a union fitting or use a radiator hose in the place where you had to cut, that way you'll have a disconnect for future use.

From your description, it sounds like the pump is working, it either can't maintain prime to draw water from the pool, or there's a blockage after the pump.

If your PSI is 0 and you have air in the pump basket, the impeller and pump should be ok because it is pulling water out of the basket and air into it. This usually a good indication of a blockage on the suction side.

I know you said that you tried to clear it but perhaps your first try was not successful. Although a rag around the hose to try and clear but this does not always work well. I would get a drain king from the hardware store for your pipe size and try that. It allows for higher back pressure than the hose and rag trick.