Just confirming stevemcmli's comments, I too have driven round Kingman without any issues. The only other people I saw there were Dutch spotters. Well worth a visit. There are no organised tours but if you particularly need to go airside then would suggest contacting the airport operator in advance of your trip.
I don't know anything about Seligman. I stopped off there once a few years back but there was nothing there (not even one aircraft!). Maybe thats changed now but I cannot see any references to it being used for storage.
Not sure where else you are going, but would suggest Tucson (the main airport), Falcon Field (Mesa), Goodyear, Marana (strictly no admittance there), Davis Monthan, Avra Valley, Ryan Field to name but a few.
Enjoy the trip.