I agree with you in large part, but not completely. In addition to the need for executive orders to execute the constitutionally-valid laws passed by the Congress and signed into law by the President, there are functions of the executive branch that simply have to do with the execution of the President’s constitutionally-spelled out duties. Congress has no legitimate authority over those functions.
I hope you don’t get me wrong. When it comes to national defense and war-fighting, the framers of the Constitution gave both the executive and the legislative branch vast powers.
The incredible tension between those constitutional powers vested in the two branches is constant. And frankly, I think the framers wanted it that way.
I agree with your take on EOs; there are some things that go with the territory. But every EO should cite its authority for issuance, whether constitutional or statutory.