Off the top of my head, a typical synthetic is 220C to 230C. Haven't used non-synthetic in decades so I'd have to look it up. But I've been told it gets tricky when you have to account for mechanical vaporization, pressures, diesel effect and contaminants.
Some countries have regulations on air compressor outlet temperatures to reduce the likelihood of explosions in compressed air systems. I don't know the numbers, but somewhere in the neighborhood of 140C seems to ring a bell from when a former employer had some decommissioned for high outlet temperatures. That was in Germany, I don't know what OSHA has to say, if anything. That should be well below flash temperature, but I'm sure there's a basis for the number... the Germans aren't known for under-engineering.
My rudimentary understanding is that long-term, lack of pump maintenance creates a vicious circle. Heat causes carbon buildup. Carbon buildup creates more heat. Most of us aren't running our compressors at high duty cycles day in and day out, but that can be good or bad. I suppose the totally paranoid homeowner could stick with oil-free units, but we all know their limitations (CFM) and drawbacks (noise being one of the primary ones).
I did a critical reading from the first link that you provided (above):
http://ncsp.tamu.edu/reports/WorkCover/Alerts.htm
Text from link:
(my comments in red and are directed at the author of the article)
Recently an air receiver of a compact air compressor unit exploded in a panel-beating workshop, narrowly missing an employee and causing material damage.
Compressors of this type are commonly used in smaller businesses, like automotive repairers, for spray painting, vehicle hoisting and other applications.
Although there was corrosion on the inside surface of the cylinder, the explosion was probably due to poor maintenance of the air supply line.
(Conclusion does not mention removing and cleaning the air supply line to prevent future explosions. No accident report, failure analysis, or details mentioned. No discussion of how the conclusion was reached or if the investigator of the accident was a professional or recognized authority.)
How can an air receiver tank explode?
During operation, deposits of lubricating oil tend to build up in the line supplying compressed air from the compressor cylinder to the air receiver.
(If this is the case, why don’t manufacturers install oil or condensing traps preventing oil from entering the receiver?) As the diameter of the supply line decreases, the already high temperature of the compressed air rises further to a point where it is possible for the contaminant to ignite.
(Evidence, citations, sources???)
Sparks are then carried into the air receiver where oil from the compressor, which is often present as a mixture with air in the air receiver, burns explosively.
(If this is the case, then why don’t manufacturers install internal spark arrestors? Should I put backflow preventers on my compressed air lines to prevent combustible gases from igniting and blowing up my air compressor receiver? Nonsense!) As the pressure relief valve is not designed for such an event, rupture of the air receiver vessel is likely to occur.
(Why bother with safety valves then? Sandbag bunker, maybe?) In other air compressor accidents, static electricity sparks have also been identified as a source of fires and explosions.
(Huh, where??? Internal static electricity in all metal vessels?!?)
Prevention measures
To avoid such incidents and damage, all air compressor equipment should be maintained in a safe operational condition and be regularly inspected. To prevent excessive fouling of compressed air supply lines, only the grade of oil recommended by the manufacturer/supplier should be used in the compressor.
(Why didn’t you say that the wrong type of lubricating oil was the cause of the explosion before?)
Sorry, but there’s nothing here but a scattershot theory backed with conjecture and supposition. If an air compressor is making combustible gases from its lubricating oil, no one should be using one.
I did read your other links and I can post my comments if you wish.
The most dangerous tool in the garage is me. 
So true.
All of the products I work on have to pass ESD testing though, and humans are modelled as a 100 pico cap charged at up to 35 kV. Low energy, but that potential can jump a pretty good distance in not-so-obvious paths. We don't see most ESD discharges in their entirety with our eyes, but the cameras catch them. I can't rule out static electricity as a source of ignition of a combustible; it's not uncommon.