[Fire General] k3ll0gs:
I have had a suspicion that the Fire 7 is hardcoded to recognise WiFi only for OTA updates and account registration etc. So I reset the device, set Amazon registration for later and did not join my local WiFi network. Plugged in my OTG Ethernet, opened a browser in Silk and went to BBC to confirm connectivity.

Since my device updated automatically the other day, even after a reset for this exercise the build is still FIRE OS 5.0.1 which is to be expected. I am unable to test if OTA updates will still kick in automatically when using OTG Ethernet?

Amazon account Registration is hardcoded to look for a WiFi connection only. Attempting to register with Ethernet does not work, the device simply prompts to join a WiFi network. [A Network Connection is required to complete this task. Please connect to a WiFi network].

System Updates button when pressed searches for an update - as there are currently no new updates again I am unable to test if this would automatically kick in via OTG Ethernet.

OK in the long run it is not feasible for the device to stay tethered via an ethernet cable, but it shows that the Fire 7 is expecting specific network tasks to automatically and manually to be carried by WiFi. Even though OTG Ethernet is working the device is simply not expecting it to be there!

As it currently stands I not going to join my device to my Amazon account again. Will leave it as standalone and install Google via the APKs that sd_Shadow so kindly pointed everyone in the right direction. Would be interesting to see if the next System Update is ignored if connected via OTG Ethernet.

Update 1: Aeroplane Mode enabled on the device and OTG Ethernet has full connectivity - was able to web browse. System Updates still searched and Amazon Account signup still prompted for WiFi connection. So it looks like Aeroplane Modes does not knock out the OTG Ethernet.

Update 2: Obviously with no Amazon sign in the device is restricted to the apps installed at factory default. So no ES Explorer donwload without Amazon signin to install the Google APKs. I know many of you have been using a ADB Shell to install your Google APKs. For this exercise of standalone device without Amazon Signin I simply connected my Fire7 via usb to my laptop, copied over the Google APKs to local storage (Fire 7 Device). Opened Amazon DOCS and browsed to Local Storage and installed them from there. Gave the tablet a reboot and all good.

Update 3: Google Play works fine on the Fire 7 via OTG Ethernet , in Aeroplane Mode and with no WiFi & Amazon account signin.

Update 4: Kindle App on Google Play shows as installed on the Fire 7 - opening the Kindle App prompts for Amazon Registration. I was hoping that this app would work without Amazon registration.

Update 5: I sent a dummy email support query from the device via [Phone & E-mail support] via OTG Ethernet in aeroplane mode to see if it would actually send and it did.

Update 6: I know sd_Shadow tried KingRoot already but the latest version came out the other day [4.5.2.928]. So I tried it but it failed to get root. But what was interesting is that when KingRoot went online to look for exploits as part of the rooting process, it would only do so if WiFi was enabled. It would not dial out when using OTG Ethernet. It was worth a go, just have to be patient for someone to find a root exploit out there.

Update 7: TowelRoot does not work either. tested it with the different codes - but it checked for exploits over the OTA ethernet.