You should contact the lawyer who represented you in this case to determine what, if any, options there are for you to reduce, or even work off this restitution obligation. It certainly won't go away if you ignore it, but it may be possible to seek a reduction, or find a program that would allow you to get some credit against the obligation.
He would serve roughly 22 months. If you go to the BOP.gov website, you should be able to see his expected release date. Even if the camp had RDAP, he might not be able to get in with only a 24 month sentence, BOP often requires that you have 36 months or more to serve in order to qualify for RDAP.
Your boyfriend needs a lawyer, and you may need one if you are saying you made a false report to the police. You should speak with a good criminal defense attorney before going further, but you could make a statement to court and ask the judge at a hearing to dismiss the no contact order. You do have to understand that you may risk prosecution for saying you overstated the case to the police.
Obviously you got the ticket, so yes, you can get the ticket. The question, as pointed out by my colleague is whether or not it is enforceable. That there was no notice that you cannot park there is a defense and one you could raise in court at trial. You might want some photos of where the car was parked and the area surrounding to show the location of, or lack of, no parking signs.
As my colleagues noted, it is six levels below the offense. Sentencing though, even in federal court is not a fill in the blanks math problem, there are a number of factors that go into sentencing and the sentencing guidelines are just one of them. This person should contact a lawyer and consult with that lawyer about the case.
Contact a good defense attorney in Broward County for advice on how to deal with this. As you have already figured out, it will not go away on it's own. And it is too complex a situation to resolve by yourself.
As my colleague noted, those are not affirmative defenses. The government has to prove it was not self defense beyond a reasonable doubt. If you are being prosecuted, you should have a lawyer to represent you, this is too complex a situation to handle on your own.