The Heller/McDonald cases didn't answer any of your questions. In fact, Justice Scalia, writing the majority opinion in Heller, made a point of saying that what specific weapons were allowed, who could possess them, when and where they could be carried, etc., could still be subject to "reasonable" regulation. (This part of the opinion was even cited approvingly, recently, by the Brady Campaign.) This, however, was "dictum," that is, material in the opinion that was not essential to the outcome of the specific case.
What the Heller case did establish was that possession of "commonly accepted" weapons (handguns) for self-defense, in the home, was an individual right, and not dependent in any way on "militia use." The McDonald case went on to further determine that this was a "fundamental" right that applied as against state governments, under the Due Process clause of the 14th Amendment. Anyway, it would be hard to argue that suppressors are in "common use" and therefore protected under Heller.
The Heller and McDonald cases raised as many questions as they answered. The opinions in those cases, from a gun owner's point of view, were rather poorly written. But we need to understand that courts don't like to go beyond the actual issues as they are framed in the case before them, and will sometimes take "shortcuts" to arrive at a result. It's going to take a lot more litigation to determine the true parameters of the 2nd Amendment.
but any thoughts out there from someone with some legal grasp of the matter.