So I'll start this off by saying that up until a month ago, I had no idea that flat earth theory was even a thing, but I suppose I should have guessed at it, what with there being theories about all sorts of stuff far more outlandish that this. However, I'm left with a few questions, and commenting on the YouTube videos I watched didn't produce any helpful answers. To be honest, a lot of them didn't make sense, but I'm not sure if that's a language barrier, the person not really knowing what they're on about, or something else. Being curious about stuff like this, I figured it might be an idea to post questions here, where I assume there are people who know the theory they're on about - experts in their field, so to speak. I should probably say that I find most, if not all of this, a little unbelievable, to the point where I'm not sure if the video makers were just putting in their own bits because they personally thought they were true, or if they are actually pieces of flat earth theory.

One video I looked at said gravity wasn't a thing, and that the earth (which was a disc) was rising at a pace of 9.8m/s (or whatever gravity is). If this is the case, why do all the planets move at the same speed, or thereabouts?

How thick is the earth supposed to be? And what's underneath it?

If the earth is flat, how is it winter in England, but summer in Australia? I've lived in both these countries, so I know that it isn't a scam or something. One guy tried to tell me Australia wasn't real, which I don't beleive, on account of me having lived there.

Why do photos of the horizon at high altitudes appear as curved?

On photos of the globe from space, why do continents 'go behind' the flat earth?

Why isn't it sunny all the time? Shouldn't the sun just light everywhere up?

I realise that those are bunch of random questions, but I'd quite like the answers to them, not in any mean-spirited 'I know you have no real proof' way, but out of genuine curiosity. But anyways, a few of the videos referenced a 'dome' of some sort, which I think is meant to refer to something that isn't quite a dome. Someone told me it was made out of electromagnetic energy, but I'm fairly certain electromagnetism doesn't work like that... And if it was made out of glass, or some space age plastic, then it would have to be man made, and I'm sure we'd have photos of guys on a ladder making the dome. Or crane. So how does the dome work exactly? And where does it come down? Unlike the lies I was told about rainbows as a child, surely I can find the edge of it if I just pick a direction and walk in it (hypothetically speaking. We're presuming I could bypass mountains/oceans, and endure cold and heat all all the other logistical issues that would crop up).

And my last one (probably won't be my last one), is that if the flat earth/round earth is meant to be a conspiracy, why is the government hiding it? What do they have to gain?

Anyways, those of my questions (for now). I appreciate that they're a bit random, but like I said, I'd quite like some answers to them. I realise I could have googled it, but there's no fun in that, and at least if I'm 'talking' to people, I can have it better explained to me. As a last bit, a lot of evidence seems to burden of proof, as in 'I don't need to prove it, you need to disprove it'. Personally, I don't view this as evidence, on account that I could claim the earth is a pyramid shape and there be 'evidence'. So if you're planning to whip out evidence that you want me to disprove, then I'm sorry, but it doesn't mean much to me.

Anyways, I've started off civil and amicable, so I'd appreciate it if any responses were the same. I know people don't like their beliefs being questioned. (It seems to have struck off the last paragraph or two. Not sure why. They're still relevant).