It now seems that you do agree that Federal judges actually have the ability to order the Executive branch on matters which are not at the President's discretion, yes?

Your thesis is that only the Supreme Court gets to decide what is and is not part of the President's discretion?

So for the three months with the Supreme Court is out of session, there's no constraint on the President, except by having an emergency session?

Is it part of the President's discretion to imprison Supreme Court judges at Guantanamo?

If he does that, I believe your view is that no Federal judge has the ability to order the Executive branch to stop.

Sounds like you've listened to too many anti-democractic activists for the unitary executive theory - a view common among the rich and powerful, and their sycophants.

The limits of judicial review are absolutely contested, and there's a perfectly respectable argument that Marbury v Madison was a wrongly-decided power grab by the judicial branch (albeit now settled law). But it's a long way from there to the idea that district courts have no JR power. They are fully constitutional and exercise the 'judicial Power of the United States' as does the Supreme Court. Subject to being overturned on appeal, of course.