Are your glow plugs coming on at all? You should be getting 10 seconds before starting on a cold start.
The big plume of white smoke (mixed with grey as well maybe?) Is all the diesel fuel that has been injected into the engine during all the cranking. Its to be expected that a mess will result when the engine finally starts to purge it out. It is going to clatter and know loud until that accumulated fuel burns out of the cylinders and exhaust ports.
For timing, look at the top of the injection pump where it joins to the front drive gear housing (the semi circular thing on the top front of the engine where filler neck connects is the drive gear housing).
You may have to wipe some grease or dust off the top of this joining area, but if you look closely, you should be able to see two small scribe marks right at the joint between the injector pump and the gear housing. If those are lined up, don't mess with the timing, at least not yet.
Get it started and give it a chance to clear its throat, then assess weather it needs timing to be adjusted.
Here is a testing method to see if your individual glow plugs are good:
1: Disconnect the glow plug that you are going to test
2: connect a 12V test light to the glow plug and touch the probe to the + side of the battery
3: if it lights up, the plug is good, if not, the plug is bad.
If you don't have a test light even a length of wire will work. If the plug is good, you will see a small spark when you close the circuit.
If any glow plugs are bad, do not use anything other than motorcraft/beru glow plugs.
I try to discourage people from using starting fluid on diesels especially higher compression diesels like the 6.9. I won't go into details about what can happen, but internal damage is possible especially if you don't disable the glow plugs.
Here are some safer alternatives to using either:
1: gasoline soaked rag on the intake of the engine
2: a high power (1500 watt) heat gun pointed down the intake of the engine while cranking
I know they sound goofy, but they work. I can actually start start my truck in the winter with a heat gun and no glow plugs.