You misunderstand the point of an aircraft carrier. It’s not any more defensible than other large, floating objects - but first you have to reach it, and the aircraft it carries are capable of blowing up nearly anything to kingdom come before it gets anywhere close. Carriers aren’t for defense. They’re for projecting power.
I live in a hilly area. Any time someone with projector headlights is on even a slight downward curve that I’m facing, it’s the equivalent of brights in my eyes. Even with adaptive headlights, cresting a ridge would still blast anyone on the other side for the short amount of time it takes for your car to realize there’s someone there.
For point 3… You’re right, and you’re wrong. Light from point sources instead of diffuse sources is worse for your retina. The light gets focused by your eye’s lenses onto a much smaller area, which can potentially damage the sensitive photoreceptor cells. Ideally, there would be regulations that limit a headlight’s candles per mm^2 rather than just overall candles. Astigmatism makes it so the light glares across half your vision, which makes it worse for seeing other things on the road besides the headlight glare, but conversely makes it better for not murdering your retina because the light is spread across a wider area.