It cranks, it sparks, has new fuel filter & pump, timing belt looks OK, but still won't start. Help, why?

INFO:
+ 1999 Ford Escort Sedan 2.0L SPI engine with 128K miles
+ I haven't been able to get/keep the engine running since Sat-18-Aug when it died in the middle of driving.
+ no engine codes/lights/indicators
+ engine started and ran/idled for ~5min Sat-25-Aug then died (has not started/run for more than a few seconds since)
+ the engine makes a knocking/clanging sound when it starts to turn over
+ engine cranks, turns over, and sparks
+ it has new spark plugs (w/ correct gap) & spark plug cables as of 3-Sep'12
- the old spark plugs did not look so bad, just black, but gap was too small at 0.045 vs. Spec of 0.052-0.056
- new spark plugs now have correct gap at ~0.53 each
- old and new spark plug #4 shows what looks like metal dust/particles on threads when removed (they stick to plug which is slightly damp with fuel
+ battery is new as of Jan'10, reads 12.5-13V not running, and ~9.5-10V under load (during crank). This is expected to be good
+ it has new fuel filter & fuel pump as of 31-Aug'12
- both old & new pumps would turn on when key was in ON position (before cranking)
- I could blow air through tube between fuel pump and fuel filter, as well as after fuel filter to valve at fuel rail
- fuel pressure on old pump was too low for spec at ~39psi not running and same running
- fuel pump spec: 50-85psi not running & 25-25psi running
- new pump is only 5psi higher (~45psi)
- EFI system does not have a fuel pressure regulator which would return fuel to tank, but instead a fuel pressure sensor within the fuel rail which measures pressure diff between fuel rail and intake manifold and then talks to PCM (as does the temp sensor), which then [the PCM] decides the needed fuel pressure and tells pump to act accordingly.
+ I tried jumping car after new fuel filter & pump, but it was no help
+ timing belt and pulleys look OK
- timing of camshaft pulley (top) and crankshaft pulley (bottom) both line up pointing up while piston 1 is TDC
- piston/spark order is left to right 1, 2, 3, 4 and firing order is 1-3-4-2
- crankshaft turned 180deg CW shows piston#3 at top, +180deg=#4 at top, +180=#2 at top, +180=2 complete turns and #1 back on top along with cam&crank marks pointing up
- pistons don't move when pressed with screwdriver through spark plug hole
- all pistons look dark, rusty, nasty, but view is dark and limited
- Turning the crankshaft (bottom pulley) required a cheater bar and great force at some times of rotation (not sure if at each 180 or only at 360 turn.
+ I read that it can be hard to turn when a valve opens
+ replaced the drive belt (not timing belt) Tue-4-Sep; old one had underside cracks, felt brittle, and just barely starting to fray in a few spots.

HISTORY: several months ago (end of 2011-2012 winter in western Idaho) starting was rough and it sound like something broke, stripped, or jumped (it was a single loud short clank/crack sound), but it was cold & rainy and so I just went on with work that day (car started up). I checked later that day and did not see any broken pieces or anything out of the ordinary. I thought maybe a fan blade broke off, but it was fine. I had an overheating problem at about that same time, but fixed it by filling up coolant reservoir (happened at winter-to-spring transition. During this past summer I would have intermittent hard/noisy starting usually in morning when starting engine to go to work, and then frequency increased to happening also at work just before leaving to go home. Frequency increased, but I was always able to start driving and at higher speeds the rough performance/sound was not present. Saturday 18-Aug was the first time that my engine actually quit working.

SUMMARY: Engine cranks and turns over, spark is good, fuel seems OK at pump and filter, but still need to check fuel rail, pressure sensor, & injectors. See check list below:
TO DO:
-- check compression (I have a rental compression tester on hold in my name at autozone)
-- check fuel rail, injectors, & pressure sensor (not sure how yet, but I know specialty tools, cleaners, and test rigs exist)
-- check for vacuum leaks (spray brake cleaner around air intake tubes)
-- decide when is best to have expert look at it
-- decide on what amount of money is too much to continue working on this
-- check guts of engine?