In the frequency database, are there any specific categories from which to choose to import NIFOG and AUXFOG frequencies without having to manually program those specific frequencies from a list?
NIFOG frequencies are listed in the Nationwide database and are part of the database internal to the radio, so if you're using location-based scanning and have the Interop service type enabled, you'll be scanning them.
If you're setting up your own Favorite lists, you can manually download and create a list of the frequencies you want (for example, 800 MHz interop) using Sentinel or any of the other software packages.
As far as AUXFOG, it depends on which frequencies you're looking for. The specific frequencies listed in the AUXFOG pretty much mirror the NIFOG and are already in the database. Amateur frequencies, apart from the standard nationwide frequencies already in the database, are typically assigned as needed for a particular incident and aren't listed in the AUXFOG nor in the RR database.