Is bluetooth supported? Will I be able to use a mouse or keyboard via bluetooth?
Currently, bluetooth is not yet supported, although it is currently being worked on. You may see your devices listed in the bluetooth applet, but you may be inable to connect to them. There have been some reports of people being able to connect, but this has not been reproduced.
You can follow the progress of implementing bluetooth on the Nexus 7 here: https://bugs.launchpad.net/ubuntu-nexus7/+bug/1070770
For now, we suggest using a keyboard and mouse via an OTG cable if you plan on doing a lot of typing on the device.