Anyway, I wanted to let everyone know that this morning I was finally able to get tethering working via FoxFi on my GS5 and PdaNet Tablet on my old GS2. I left the devices unpaired in Bluetooth settings, then started the bluetooth tether on FoxFi, then went through the PdaNet Tablet configuration. It found my GS5 and paired, then connected. I verified by visiting a website and testing some apps.
The whole point of this exercise was to get Ingress working so my son can play with me. He has my GS2 now. Not having tethering thus far has been the only missing piece of the puzzle, but this is a good workaround until root is achieved.
I assume this would also work on an Android tablet, but I haven't tried that yet because my old Transformer's charger has failed. I will also experiment with a laptop & bluetooth dongle, and also my iPad.