I agree that the world and the sky have shapes, obviously.

For example: if the Earth were a flat disc, and you put a light above the disc, anywhere, it would be visible anywhere on the disc.

This is a common misunderstanding. Light is not magic, it can’t travel forever for a myriad of reasons, and it is only visible if it reaches you (even when it is, initially, bright enough to do so). One of the primary reasons such light can’t reach you anymore is due to the density gradient in our air which tends to divert light traveling through it convexly towards the ground, but there are many others.

Surely you don’t think you could see a candlelight or small led that was high in the sky - especially not from another country! Like most everything else, this doesn’t vary regardless of the true shape of the world.

If the Earth were a globe, and you have a light at some distance, there will be a point closest to the light, and a circle centered on that point will represent the barrier past which the light is no longer visible due to it being blocked by the curvature of the globe.

Possibly, yes. If the world were a globe that is. If it were not a globe, then this would be a non-real, and incorrect, imagining.

Similarly, those of the “spotlight” view think the same thing happens just without being blocked by any supposed curvature.

It's pretty obvious you're talking out of your ass here...

I have many alternative and unpopular views, and consider many others. I think i have thought them through and have adequate evidence to support them, the same as you do.

The question is, how can we best determine which of us - (if any!) - is correct?

and you put a light above the disc, anywhere, it would be visible anywhere on the disc.

We all agree there is an atmosphere, right? And how light is effected by it? Are you retarded or ignorant?