They weren't asked that question. Why would they answer it?
The question before them was if the tax stamp requirement on a sawed-off shotgun violated the second amendment. THAT was the law that was violated.
If the law stated that only militia members were allowed to transport a sawed-off shotguns interstate, then certainly Mr. Miller's militia status would have been relevant. But anyone was allowed to transport a sawed-off shotgun interstate -- provided they had a tax stamp affixed. You keep making this hypothetical the issue when it wasn't.
"By showing that pistols are militia weapons and were in common use at the time, the Parker Court completely side-stepped any issues with Miller."
Side-stepped? They waded in!
The Parker court examined Miller, came up with a "two-prong test", and faithfully applied it to their case. The U.S. Supreme Court appears to have accepted this two-prong test, and added a third -- lineal decendancy.
"They only need to agree with Miller that the people, including Heller, have the right to keep and bear arms that have some utility to a militia...."
AND .... AND .... are in common civilian use. That excludes a whole bunch of weapons -- .50 bmg rifles, select fire M-16's and M4's, machine guns, etc.
You're getting far, far ahead of yourself and the Court. No decision has been rendered yet. And the Court has to become quite skeptical of adding more and more strictures to the word "arms" with no justification to do so.
And your statement that the Miller Court wasn't asked about a requirement for militia-membership is false. The prosecution's argument summary clearly contained the statement that only members of a militia should be protected. The Miller Court was free to establish that as the standard if they wished.
We have been over this ground before. You continue to state falsely that the NFA 34 is either Constitutional or unConstitutional without regard to the status of the person being affected by it. That is simply not true.
The Court is perfectly capable of permitting the enforcement of the NFA 34 with respect to some defendants and not others, just as in Miller they were able to permit prosecution with respect to some arms with no question whatever regarding the other arms included in the law.