Welcome!
I'm a Flat Earther, but probably not the one you are looking for, since I do not believe in many of the ideas you question. Nevertheless, I'll try to answer them as best I can. Also, there are further answers for these if you go looking, but I figured I may as well help you out.
1. Some believe there is land and resources beyond the Ice Wall, and this is hidden so these resources can be exploited. Others believe it has just become too big of a lie, that if the truth were revealed, it would show how dishonest the government is, which is why it's kept secret.
2. There are many theories, including density (something rising or sinking based on displacement of air), and even that the Earth itself is rising (although I don't think anyone believes this here).
3. As far as I know, there are no pictures of the flat Earth. I haven't seen any yet.
4. Personally, I believe that apart from what you mention, it is completely flat, although many others here do not.
5. I don't know, sorry. I believe it is a solid ice barrier that surrounds everything, but I actually haven't seen too many people talk about the dome.
6. I believe the moon is real, as for it's phases, again I'm not too sure what others think. Sorry I can't be more helpful on these two, but if you look around there are answers to these questions to be found here.
7. Many of us think other planets are flat, too.
I hope that's answered a few of your questions, if you're still curious or my lack of knowledge shows, there are thousands of times these questions have been answered if you look a little into these forums.
Again, welcome!