Well, you've done a lot. O-rings will not mess with timing, that is mostly controlled by computer now though some may still be somewhat mechanical. You say it doesn't run the same as before you changed your fuel pump %26amp; filter and I surmise that you've tried the other things in response to that in an attempt to fix the problem. So, if that's the case, then I would look more at your fuel pump %26amp; filter, even though they were just replaced, as your problem occured after their replacement.
You say it seems to run out of gas, this could indicate that the fuel pump is: not the correct one, not installed correctly, defective, tubing that connects it inside tank is damaged (has a hole, kinked, not securely attached, clogged, etc.), or possibly your fuel line hose is pinched between fuel tank and car body/frame when you put it back.
Your fuel filter could also be installed incorrectly or clogged from possible debris from changing fuel pump.
At any rate it sounds like you are not getting the proper flow/pressure of gas that you should. A pressure test of your fuel system will probably show that you are losing pressure at higher RPM's than at idle which will not necessarily point to anything specific other than it is low. You would need further diagnostic testing to determine the most likely cause.
Best of luck. Hopefully I've given you some things to think and check on.How do you test a fuel pressure regulator? Would the O-rings have a part in messing w/ timing?
Attach a fuel pressure Gage to the feed line and unplug the vacuum line from the regulator while the car is running. the pressure should increase from about 40-45 lbs. to approx. 10 to15lbs. higher. o-rings have nothing to do with timing.
