The GG made the best decision at this point.
Although proroguing the parliament seems like Harper is buying time (Which it is...)
You don't want to call hand over power to a last second coalition or call an election on the turn of a dime.
Now there is a cooling period with a definite time frame (I would have a problem with a prorogue with no end in sight) where Harper either regains confidence or loses it when he comes back.
If Harper loses the vote in January and the coalition is still in one piece then u will have indirectly tested the stability of the coalition and could let them form government. If Harper loses the vote and the coalition doesn't exist then we have an election.
As to who is in the coalition etc, the GG cannot deny a coalition based on its members...that is a political decision which has no place here.
So all this talk about denying the coalition because it includes the Bloc is absurd. The system has to work consistently regardless of the parties involved.
This all fits in our constitutional custom and tradition without breaking anything.