Cashew its like saying refraction exists through solid mediums - liquid mediums - and gaseous atmospheric mediums... Its an established phenomenon. We can argue how much atmospheric refraction exists which I think is your general point.
I can give you a few numbers as to what the diameter of the earth is, sun, moon, and distance between them but its really not worth it.
But generally I'd put all my distances within thousands of miles which is similar to some general FE theory.
1. Yes, my first point is that using a solid glass dome to simulate your model would be an inaccurate setup.
2. It would indeed be worth it to having an experimental setup that mimics as best as possible the scale of sizes and distances to which you are testing.
- for example, if the small spotlight Sun is the same as general FE theory (~30 miles in diameter) and your flat Earth assumption is say 7,900 miles, than that would indicate that in your model the Sun would need to be 263 times smaller. The spotlight in your model would be quit small, almost like the size of the head of a pin (vs. a large flashlight bulb) if you wanted to use something similar in size to what you are using to replicate the flat Earth.
- The distance of your small Sun would also need to be positioned to simulate being about 3,000 miles away, which would be a less than half the diameter of your flat earth model.
- Do you plan to adjust your setup in this way?
3. In terms of your mention about Voyager 1, my comment can be addressed in a different thread and debate, but it would seem to suggest you believe in or are open to the notion that NASA has gone to space and that space travel exists. If that be the case, than some questions to you would be what do you make of the pictures NASA has taken and published over these past few decades showing a Globe Earth and Earth's curvature? Again, this is for a separate debate but something to think about since you mentioned Voyager 1.