Modern trucks, even with emissions controls, are more powerful than anything older. Engines are more reliable if anything, though there are plenty of pesky non-engine electronics ruining the useful lifespans of modern cars.

If you're talking about black smoke out of the exhaust, no it doesn't help reliability. If you just mean tuning to optimize not for emissions, yeah it can help if you know exactly what you're doing or screw it up if you don't, either way you'll only find out later. Doesn't seem to matter because professionals already survive without messing with their trucks.

idk who downvoted you, that's not appropriate, so +1'd you to avoid comment death