Staying on the topic of the install issue for a moment, I think there is a partial install of the Cayenne agent around from a previous install attempt that is throwing things off. Try this command to delete it:
sudo rm -rf /etc/myDevices
then re-run your
sudo bash rpi_xxxxxx.sh -v script again. If it fails show me the new output.
If you post your output from
uname -a I can confirm if you have the incompatible kernel. I've not seen the downgrade command fail like you described above, but if you share with me the output from attempting it I can have a look and see if I can find a solution for you. Either way the whole kernel thing won't impact install, so I'd focus on installation first.
Finally, I'm going to say our website just wasn't designed with a tablet browser in mind -- I do apologize for that since it should work if its not forcing you to the App Store, but you're missing 'Back' and 'Next' buttons that are necessary for you to navigate:
I wouldn't worry about it because you have an invite code as I can see above, you don't need to generate a new one, we should be able to get you installed with the existing one.