I read this whole, long article, and I don't understand how you're freaking out at every. single. step. although you do say the visa thing is the root stress.
But you seem to be freaking out even at not getting on-boarded immediately or that you don't have detailed explanation of what you will be working on the first day, or that you're not immediately invited to all the meetings. I work at Autodesk. This is completely normal, it takes a couple of weeks to start on a team and not everything is clear, especially if a key person just left. This isn't a job at Burger King where everything is clear. Also, nobody is going to structure their vacations around you. Some head count is getting allocated, and then filled, often with huge delays, and that person arrives at a certain date, and while people know it's coming, it's not necessarily a good time for anyone, it is forced on us. It's troublesome to onboard the intern or new employee and it gets past around like a hot potatoes sometimes. And no, often there isn't any documentation. I've onboarded probably over 50 people over 20 years.
It sounds like you arrived after the project was just sent in a tailspin and people are having meetings just to figure out WTF is the state is the state of project, and you shouldn't have expected to be invited to all those meetings, as you have nothing to contribute as junior and the people probably weren't sure of anything. It's normal. Also, that iBuddy yapping about the previous guy getting fired? We can't know the context, have you thought that person was hugely stressed about it too and sharing that earnestly? I mean, they're on the sinking project as well? And at least she's talking to you and putting you in the context of the team. Insensitive, perhaps, but again the world isn't going to rearrange around you.
At one point in the story, you're clearly falling into a depression, and seeing everything dark. A manager repeatedly cancelling and re-scheduling a meeting isn't a plot to harass you: it happens a lot to busy people, we don't know what kind of crisis he's dealing with. During this whole thing, you just assume that everyone is just taking off, missing work, and focused on you. These people might actually be going through crisis on their own and having to put out fires left-and-right.
This last bit, where you get a meeting in a locked abandoned building you think nobody should have access to, and you ask the senior director to leave because he wasn't invited: You realize that's paranoid thinking and crazy behavior, right? When you need to have a HR-type meeting with an employee, you have it in a private place -- for the employee's benefit! It's for you that it's in a private place, away from other people's prying eyes. Then, of course, the whole point of the meeting is to have the senior director talk to you, that's what the meeting is, he didn't show up unplanned. He's not on the invite so that you're not too stressed on the way. The idea that they're keeping it secret and deleting the meeting from the calendar to hide it is just paranoid delusions perhaps caused by depression. It's the way it's done. These meetings are happening because you're in deep shit, it's very rare. The director is offering you to leave on our own so that you can leave with your head up and on your own terms, and not have the record of having been fired. It's a kind of curtesy. This might sound horrible -- but firing someone is a last resort.
Now, don't get me wrong. I've hired people from india, china, singapore, and other places. I have no doubt that you have suffered inappropriate comments and racist behavior. But we don't know the full story! I've had to fire people as well, who seem to do a lot of work, but a lot of useless work that needed to be redone, or get stuck into rat holes for week without asking questions. These people all thought they were doing as best, and got multiple warnings and "PIPs" (Performance Improvement Projects, as you know) as they could and no doubt had a lot of fingers to point after they were let go. It's always other people's fault.