3) Why isn't this study getting more attention?  If it can enable dopamine neurons to recover some function would that not be amazing?

On Parkinson's disease websites patients have taken notice and every patient has or is trying NAC.  The same reason why NAC is being tried by Parkinson's disease patients is the same reason why it is not being explored by drug companies:  it is inexpensive and readily available.  There is no profit to be made from NAC.  The anecdotal results thus far have been positive.