You still need the MID (or whatever type of headunit you had before) in order to see the OBC readouts and reset/adjust them, such as fuel consumption/timers/etc. However, in order to perform some coding, such as automatic doors locking, this can be done with the MID taken out too.
For instance, at some point I had the 16:9 unit busted and I had it removed to pass it to a repair shop. During this time, I could still mingle with the NCS and change all the values in there.

As about the stalk issue, what exactly is not working? If it is an ibus issue, you should find some error stored, such as "..telegram timeout for whatever module..".