Not sure if this specific idea has been suggested before, but can we please have a 'Do This Next' button in the PH and Barracks.
I have lost count of the number of times I have had a long queue of things waiting in one or other of these buildings and suddenly realise I need a particular type of troop urgently, or need to queue up something like a Golden Brew Mug for a Guild Quest, so some mechanism to be able to move a particular job to the top of the waiting queue seems like a real 'no-brainer' of an idea to me.