Man, we have executive imposition of regulations since the very beginning of the republic. Hamilton's treasury department and customs. The 1792 postal act.
You can't have an effective executive without some kind of rulemaking authority.
Marshall wrote in 1825--
"The line has not been exactly drawn which separates those important subjects which must be entirely regulated by the legislature itself from those of less interest in which a general provision may be made and power given to those who are to act under such general provisions to fill up the details."
(And, of course, subsequent decisions have helped to draw that line more exactly).
> adjudicate violations of the regulations
You can always go to a real Article III court, but you need to exhaust the remedies within the agency first.