... Still Won't Start...

If the engine light is on what is the code?

Ok Nick, first -- I know this is very frustrating but you must keep your head. Do not scatter your thoughts all over the place. Trouble shooting any problem with any computer controled engine is a step by step process. You must first determine if you have spark. If you know how then do it your way, if not get a cheap spark plug tester at any auto store. Preferrably the kind that you hook right up to the wire. If no spark test the ignition module. Remove it and Autozone or a place like will test it for free. If still no spark, check the coil. Take it to the place you tested the ignition module.
I don't mean too say you cannot test the ignition module or the coil yourself; it's just easier to take them to a place where they have the proper equipment and---if it is indeed bad--- you can get a new one right there.
It's probably your ignition module (simple fix). If the engine just stopped all of a sudden going on the freeway I dought it is a fuel issue. So lets rule out a spark issue before moving on to a fuel issue. Fuel issues tend not to happen so suddenly. But ya never know. Don't worry we'll fix it.

Is there any spark at all? Why did you replace the coil? They sell cheap spark plug testers at autozone.
Also you must find out what the check engine light code is. This will get you to the answer quicker. Autozone will scan your truck for free. Stop changing things unless you test them and determine that they are bad. Autozone or a place like that will test many things like coils, ignition modules and almost any sensor for free.
What kind of spark plugs did you put in? Bosch are junk even new ones, I suggest A/C Delco.
I also see that your battery was low and your alternator was bad. Your truck has a security feature from the factory called PASSLOCK. This system works in conjunction with a resistor either in your ignition switch or in a passlock module. This resistor has a specific value that is unique to your truck. Sometimes when the battery is low this resistror fails. The passlock system will not allow fuel into the motor if it is set off or broken. Unfortunatly a chevy dealer is almost always the only shop in town that has the capability to determine if this system is failing.
The neutral switch may be the cause also, but test it before you replace it. Stop changing things just because you assume that they may be the problem. Test them first. Jump out the fuel pump and test the fuel pressure. If you don't know how, there is a fuel pump relay in the- under the hood- relay center. Take it out and look at the wiring diagram. There are two terminals marked 85 and 86. Jump them out with a small wire. This will jump out the fuel pump directly. It should run and you then could test the fuel pressure. Do not worry about how long the pump runs because the fuel is just recirculating back to the tank. Keep me posted

Sorry, passlock came out in 96. In order to get the diagnostic code you have to let the diagnostic mode (12) flash three consecutive times, sometimes four. After that the trouble code will flash out it's sequence.
I do not mean to insult you in any way. I'm just trying to help. If there is no spark ( which you still haven't said) then there are only a few things it could be. If you have a spark tester or an old spark plug try hooking it up directly to the coil wire. See if there is spark there. If there is spark there and not at the spark plug then the distributer is not turning. I've seen the gear on some of these distributers strip out. If the ignition module is good then there is only one other thing that it could be and that is the computer.
If there is spark then hook a noid light up to one of the the injectors. If it flashes then it's a timing issue. If the noid light does not flash then its your computer.

BTW : Bosch plugs are JUNK!

The neutral safety switch will not prevent spark, it prevents fuel from entering the motor.