I always preface posts like this with a suggestion. Use the search function. A lot of these questions have been answered already here.
1. It's definitely not down. As far as I'm aware, it's still being fine-tuned and how02 is trying to make sure it's where it needs to be before it's open for applications.
2. Unfortunately you can't be invited right now. The only people that have access are people that extended their subscription from when they had the old Rust hack.
3. See above. When it's opened to the public it'll probably be an application and an accompanying application fee like the PUBG cheat.
4. I would suggest being an active member of the community and more importantly, a valuable asset. Don't just post "wow nice hack can't wait" on every post about Rust. Try and provide something to the community.
5. No clue on the Discord, I haven't seen anything but maybe someone can enlighten both of us on this one.
6. The Rust hack is pretty "new" and there was a recent PUBG release. I'm not the developer so I wouldn't know all the details.
I hope that helped a bit!