Bugs still there in 6/24 nightly
I upgraded to the latest nightly to see if those bugs had been fixed and no luck.
The WiFi region code still won't stick. No access to 5 GHZ WiFi.
The Tethering & mobile hotspot settings are not there, unless you try this workaround.
Turn on airplane mode. Reboot the tablet. Go into Settings > Wireless and networks > More... > Tethering & portable hotspot > Set up Wi-Fi hotspot. You can then set the SSID, Security, and Password. As soon as I enable the cellular radio and it connects to AT&T, the Tethering & portable hotspot settings menu is no longer there.
I can now turn on the mobile hotspot with the Quick Settings toggle. I see the SSID I changed it to. I can connect using the password I set. Unfortunately, I cannot get to the Internet. When I look at the IP address on my PC, it's an autoconfig address. The Nexus 7 didn't supply an IP address, so my PC picked one at random and it doesn't work. It appears the DHCP server for the mobile hotspot is not working.