It looks like there really isn't much I can do since Google has the external SD card locked tight in kitkat. You can try using this app to try to "fix" the issue.
https://play.google.com/store/apps/details?id=nextapp.sdfixIt's quite interesting to see that the Amazon Fire TV edition of Pandora uses some undocumented partner login credentials. I wonder what kind of content it provides...
Update: It appears that tuner.pandora.com DOES provide 192kbps MP3s, as long as it is logged in as a Google TV or Amazon Fire TV partner. Looks like maybe I can get Pandora One 192kbps MP3 and region bypass at the same time with this kind of login!
Update 2: It can also be that Amazon Pandora sends an extra parameter when retrieving playlists.
Update 3: I now get 192kbps MP3 on tuner.pandora.com using the undocumented credentials for tuner.pandora.com, as well as an undocumented API parameter for retrieving playlists. I believe this extra parameter has the power of serving 192kbps MP3 if the account supports it and falling back to 128kbps MP3 is not Pandora One. Going to test with free account.