It is entirely up to the judge, based on the factors above.

You can hire a lawyer to do this, but paying a lawyer by the hour to beat their head against the wall with Meta might not make sense.

No the U.S. government (i.e. taxpayers) will not pay for your travel back to the U.S.

If you call the cops, they will do nothing. Get a new GF if you don't trust this one.

You can hire a PI, or a law firm to pursue it.

If someone broke into your house and stole something, whether it be a puppy or a necklace, you call the police and report them.

I see several issues. One, you don't know that he lied. He may have just been wrong. Two, you could have called your own mechanic to verify. This...

In most cases, you can quit (or be fired) for any or no reason. So your decision is to spend the money suing them, or just move on. The latter is...

You can, but it sounds like a very bad idea that could lead to you being fired. But from a purely legal perspective there is nothing to stop you...

That's a dumb idea. Listen your attorney..............