Can you tell with an oil pump sitting there outside engine if its high flow, whats its condition is.
Same for sender how do you test to see if its reading correctly...

 

If you have the equiptment yes easy.
For the sender you need only apply a KNOWN pressure to the sender of whatever psi you want and see if the terminal where the wire goes on and the body of the sender have the same resistance, as it is this change that illuminates the warning light, do it with a bulb rather than a digimetre as there may still be some small resistance even when contacts have opened inside to put light out.
The pump can be physically examined look for scored rotor and plate, and play between rotor and it's outer, sometimes just the end plate can be lightly skimmed to make good.
If there is a pick up pipe on it, and a output pipe putting it in oil and spin with electric drill you can establish the pressure, not forgetting he pump speed works at half engine speed shown so if spun at say 2000rpm that would be 1000rpm engine wise.
tabetha