The Federal courts are inferior to Congress. Only the SCOTUS is a Constitutional entity inferior to no one. They can only issue decisions which the lower courts have to respect.
Congress has to impeach and remove him. This was fairly common in the 19th century but not in the last 100 years. It's seen as Draconian now which is ridiculous. Alcee Hastings was a convicted felon before he was removed as a Federal District Court Judge.
And long term the Congress needs to draw boundaries around this kind of behavior. But they won't, especially when it comes to Executive Orders, which are a bit Constitutionially suspect themselves, but not this one.
Few federal judges have ever been removed from office, it was never “fairly common” but extremely rare. Impeachment and removal is constitutionally very, very hard.
That is not true, it is just accepted by Congress since Marbury. Congress can pass legislation that is not subject to review and thy have done it many times.
Personally I think that congress likes the current method because it allows them to change the law then say the court has spoken and take no blame for it.