The ruling only has binding precedent in the 5th Circuit, other circuits aren't bound to follow it. Formerly this kind of ruling would come with a nationwide injunction to force the issue but now that those are severely curtailed by the Supreme Court it's only binding to the courts under the jurisdiction of the 5th circuit.

Decisions in other circuits can be very persuasive to other circuits but they're not required to agree the same way a Supreme Court ruling is binding. Circuit splits are moderately common and usually trigger a review by the supreme court if an appeal wasn't filed for the earlier decisions.

Only the 5th court of appeals. However if you get caught elsewhere your lawyer will have a good appeal grounds just because your area will need to decide if they agree. If all areas eventually agree it probably never will get to the supreme court. Once several different courts hear this and make a decision if they disagree the supreme court jumps in reading all the logic of everyone below them to try to find a real answer. (It doesn't always work this way, that is the textbook ideal way, but the real world is often different).

Note that unless you think nothing of spending 20 million dollars on lawyers this is probably not something that you want to fight.

Appeals court decisions generally only apply to their own jurisdiction. But they obviously hold a lot of weight when cited in others.

Prior to this year, the entire country. Today, thanks to SCOTUS shenanigans, it likely only applies to the states involved in the lawsuit, LA. But who knows, hard to keep up with the game of calvinball the SCOTUS is playing.