Ford Repair: troubleshooting, fuel pressure guage, internal combustion engine

Question
i have a 1989 ford bronco full size 5.0 liter fuel injected. i had a rebuilt engine put in it about 9 months ago.  it started running rough so i got plugs, air filter, fuel filter pcv valve and changed oil.  well my friend was trying to help and he put on fuel filter and spark plugs. it ran worst. i changed wires still rough sputtering and no power. i got under it and checked hoses wires. next day it ran lots better. i had power again.  later that day it started mising and sputtering again. so tonight i took off the fuel filter cover plate and the o ring is sitting by itself the hose barely on. i think i need new retainer clips. dont seem to be doing much. now im a single mom so trying to troubleshoot  any ideas would help. sputtering really bad might be vaccum leak. getting lost  

Answer
Jackie, the problems you're having - and the repairs you've attempted - are not what I would expect from a recently installed rebuilt engine.  If you're confident the engine was a quality rebuilt one, I'd leave the engine alone and look to components that were not replaced.
If the engine quality is suspect - TAKE IT BACK to the shop that did the work and let them figure it out!
From what you described, I'd put a fuel pressure guage on the rail and see if the pump is producing the needed 32 or so PSI, open the throttle and see that it increases to 40 or so...
If the check engine light is coming on, have a diagnostic check done to see what code is being set.  That is the best way to begin diagnosis.
When the engine runs rough, you need to determine if it is due to a loss of fuel, a loss of ignition, or a loss of compression... that's really the 3 things that make an internal combustion engine produce power.  Other items such as timing and fuel control augment the power level, but the basics are still a reference point.. For example, you can pull the SPOUT connector and make the engine run at base timing (10 degrees) and see what happens over the range of other variables.
If vacuum is a possible concern, install a vacuum gauge and see if the loss of performance is coinciding with a loss of vacuum.. frequently a leaking intake gasket will only leak and cause a problem when the engine is cold - after it warms up a little the gasket and metal swell, sealing the leak.
The fuel leak at the filter could be your problem - the Ford garter spring at the filter fitting is available - ask your dealer.  They are frequently damaged by mechanics that don't have the correct tool to release the spring clips when replacing the filter.
Hope this helps... best of luck!
Clay