So in McDonnald the majority did find that the Due Process clause of the 14th Amendment applied to the rights of the 2nd Amendment.  But also "The majority decision also reaffirmed that certain firearms restrictions mentioned in District of Columbia v. Heller are assumed permissible and not directly dealt with in this case. Such restrictions include those to "prohibit...the possession of firearms by felons or mentally ill" and "laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms".

So it seems the case your reference actually does say that "regulation" is permissible as long as it follows due process.  I don't see the issue with my version that "well regulated" doesn't mean "well regulated".