Re: Some questions regarding Truss Rod
Must be the violins playing a death march for the neck that just died because it was flexed.
Any full dive to full pullup flexes his neck further than a completely loose truss rod, which on most necks will give just over .5mm in relief, to anywhere past straight.
In a case where you have a hyper stressed neck where they will literally be bananas with a loose truss at near 2mm of relief at rest on the worst, I'd sure want to know that's what I have, and loosen the bullet nut enough to get a good layer of lube under it would be the first thing I'd do. And find out how tight and much stress it needs to get back into playing relief.
You can be a child and learn this stuff over years of being afraid to turn your truss rod and making slight movements only and checking them tomorrow, or you can learn in 5 minutes with no chance you're going to damage your neck, unless you already have a bad neck. You're putting far more stress on your neck by playing the guitar, if you play it to it's trems abilities.