First time to use this service. I will try to make this brief, but detailed.
Bought this vehicle a few months ago with a rough idle issue. Codes were for egr and no. 4 misfire. Replaced EGR and idle improved. To address the misfire, I have done the following: plugs, wires, new battery, tested coil (did myself, also removed and took to AZ. They said primary test was on borderline, but good), replaced injector on no. 4, replaced intake manifold gasket, replaced numerous vac lines that were brittle and cracked. I also discovered a small blue/black vacume check valve that had laid on the EGR tube and melted shut, so I replaced. I also have run several tanks of gas with fuel cleaner - Lucas/Chevron.
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Each step improved rough idle, but nothing eliminated the rough idle or cleared the CEL.
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While on the highway, I heard a slight, dull thump, felt a jerk, then the car died. I was on my way to the airport for a job out of state. Had the car towed home, and it sat for approx. 3 months.
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Now that I am back to work on it, it cranks but won't start. It appears I have spark (in line spark tester) and fuel (hear the pump, plus pressure at valve). After checking basic connections, I looked closely at timing belt and discovered it was misaligned. I don't know if this was before the stalling, or the cause of the stalling, but it had jumped. I have reset the timing belt, but it still won't start.
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Although I had a small coolant leak at radiator, it never overheated. I would sometimes get "coolant" light, when level dropped. No coolant in oil, no oil in coolant.
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I know compression is next test, but I have read the engine has to start for compression test.
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Between this site and another site, I have read 100+ posts. I have these questions:
1. does engine need to run for compression test?
2. Any other way to test without compression gauge (I don't have one)?
3. Because veh has sat so long, will I need to add oil to pistons for comp test
4. Are either the cam or crankshaft sensors possible causes? Seems I have read that having a spark will eliminate either of these.
5. I have read several posts that say to clean MAF. Could this cause veh not to start?
6. Read one post that mentioned a bad coolant sensor as a cause for not starting. How likely is this in my case?
7. Because veh is not running, can't get it to AZ for codes. Plus, having sat for so long, battery drained. Without thinking about codes, I disconnected battery while I charged it, so I don't think I would get codes now anyway. will the computer set a code by cranking, but without actually starting?
8. Possibility of bad grounds? How many are there, and where are they?
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I have found numerous posts with some of these issues, but not all of these issue. Also, many threads end with no resoluation. I will be sure to post an answer when this issue is resolved.

Since you said you heard a "thump" and the timing belt was misaligned ?, does that mean walking off the pulley or not setting in the pulley correctly?
You probably lost the timing belt and bent one or more valves. The compression test will tell. Pull all four plugs insert a compression gage in the spark plug hole crank engine a least 4 revolutions. Any readings under 100 PSI that cyclinder is dead and the valve or valves most likely history. That means pulling the head and having it checked and valve job.

It did not jump off the pulley, only jumped a tooth, maybe two. It seems that I have read on several posts that broken/slipped belt will not cause valve damage on this engine. Have I read this incorrectly?

yes if you was going down road and died then you probably have bent valves. but do a compression it will tell you if you did bend valve or valves. but he's right you'll have to pull head off.