Re the pressure, the easiest way to check that is with a gauge. You can usually buy one that simply screws onto the hose bib (the outside faucet). You can read it off of that directly. They aren't very expensive, say around $10 or so I've been told. I've got one, but I've had it so long, I don't remember what I paid. At least 30 pounds should be available. On the other end, if it is over 80, you should put a pressure reduction valve. Around 50-60 is a good number to shoot for. If you are trying to do something like fill a pool or something like that, it might have been nice if you had 3/4" pipe all the way to the faucet, but for most things, the 1/2" should be okay. You'd get more volume with the 3/4" supply, but it would have no effect on the pressure. It could be something as simple as the washer in the outside faucet has swollen, restricting the flow. My unprofessional opinion.