...2)I do not completely agree with this statement.
IMO, you are going to the extreme and planting ideas in the OP's head that the engine may be on its last legs when there is no evidence of that.
3)I do completely agree with this statement because I lived it.
IMO... (Based On The Engine and Systems being Stock
Replace the plug and move on.
If there is no oil in the airbox, no blowby seen with the engine running and the oil cap removed, the plugs are not fouled and the PCV valve moves freely and the line is not collapsed and the grommet is properly secured and not cracked then chances are there are no excessive pressure issues, just age.
Never implied that anything besides crankcase pressure and old cap/adhesive were to blame. Well that and the drivers right foot (lol). Just gave possible reasons for crankcase pressures. No doom or gloom. OP told us in first post that he was running high RPM's and being a turbo that would mean it was seeing boost. OP was looking for reasons why it came out and solutions.
Like I said before, I don't subscribe to the pound em in install that even the factory seems to endorse. I take the valve cover off, cam cap off. clean it, seal it with thin
bead of RTV, assemble, torque the cap on, let it dry, and it will never pop off again.
An alternative option that won't fail as previously mentioned is to run a rear cam seal not a rear cam plug. That won't pop out either. Might weep as seal ages, but won't fall out as there isn't enough surface area for crankcase pressures to act on it.
So all you guys that pound them in, you do know that most of your adhesive (RTV or otherwise) is wiped away because of the interference fit of the cam plug? So then when you lose a clutch disk because you weren't running a timing mark cover, or worse yet, lose a engine because you ran it out of oil because of that pesky rear cam plug popped out, know that you could have prevented this by IMO, a better method of installing that rear cam plug. Just sayin...
To me, pounding cam plugs in, is like doing a slip-n-slide head gasket change. Will it work? Yes, at least for the time being. Did the dealer service techs use this approach? Of course, time is money. Would they do that on their own vehicles? Not likely, as they should know there is a better way.
Is there a better way? IMO, yes, but what do I know?