Claus' comments are embedded in a PDF file.  Below are my responses.

The editorial changes have been made.

Where the discussion and analysis was noted as lacking, I have tried to
add more text and to do a more detailed analysis.

The punchline has been better emphasized in the abstract: many of these
mid-infrared diagnostics effectively constrain a target's dominant power
source.

A table listing the names, types, and references for the archival data
has been added.  I'm hesitant to add a table listing the metallicities
of the SINGS targets for the following reasons:
 a) John Moustakas (w/Kennicutt) is still working on the SINGS
    metallicities, using both his spectroscopy and values from the
    literature.  He has provided me with 38 nuclear and 51 'disk'
    (0.4R_25) metallicities.  36 of the 38, and 46 of the 51, span a
    factor of only 4 in Z.  This is still a work in progress.
 b) Unfortunately, we have IRS non-detections from most of our faint,
    low-Z galaxies.
 c) I don't specifically address metallicity in this paper, save for
    mentioning how SMC/LMC HII regions appear in various plots.  i.e., I
    don't use the SINGS metallicities in this paper.
    
The SINGS IRS group prefers to publish a SINGS spectral atlas once the
data for all 75 galaxies and 94 extranuclear regions have been obtained
and processed.

I don't see a dip at ~24um for NGC2798 LH (nor for any other system in
this plot).