I will answer to what I have tested/know.
2. Keyboard basically works but there is no backlight and correct cursors mapping. However there is workaround for this issues (check thread at xda).
3. There are also problems with sensors, no hdmi, harbour and led notifications. For example: orientation works until you lock screen, there is no charging led indication (by design?).
Overall there are many small issues like in other ports but personally I wait/search for sensors solution and I will probably use it as my daily phone. BTW screen is much brighter compared to my old n900.