First, I'm glad that you eventually installed a VM and took care of this. Thank you for your perseverance. Second, none of this requires Ubuntu specifically. I've been doing this with CentOS all along -- no Ubuntu. Finally, your adb issues may be linked to the tablet not being configured to support it.

On the tablet, look under Settings, Applications, Development Options, and turn on Automatically Enable Debug when USB is connected. Once that check mark is green, try your adb again. If it still doesn't work, you may have a process out that that needs to be killed and restarted. From a command prompt

ps axw | grep adb

and if you see a line with "adb fork-server server", locate the number in the very first field on that line (called the Process ID or "pid"), and then type

kill <pid>

replacing <pid> with the actual number from the first column. Then try adb again (from the directory where you stored it) such as

adb get-state

and see if adb starts the server and shows "device" instead of "unknown". I've been a Linux geek for 15 years, and this one bit me for a few days last week!