They held you for 15 minutes, then let you go, that would be about the right amount of time for that many officers to thoroughly search the area, the search also explains the amount of officers present, the line was closed and they would under pressure to get it open again, while I agree that officer could of been a lot calmer I don't think he was overly threatening, and for you to win a lawsuit he would have to threaten, deride or slander you a lot more than he did.
Sure he scared the poop out of you, that was his intent, he didn't want you to hurt him, or you make him hurt you, so he keeps you mentally off balance, you were not hurt, other than your pride and dignity.
What you are doing on youtube (and intend doing more) is trying to raise a mob against the police and that is not going to help you when defending yourself against the charges,
and that should be your first and only concern.
You have a letter of permission from the railroad customer service so all you have to do is prove you were a safe distance from the tracks, so stay calm and wait until after the case to lodge a formal complaint, and maybe a lawsuit, against that officer, and once again a campaign on youtube to rally people onto your side will not help, it might even result in that officer taking legal action against you for harassment, and as you have already made multiple public statements against his character, and intend making more, he has a good chance of winning.
I hope and expect that the court will not rule against you, stay cool
Cheers David