Yes, the Duke of Cambridge is a serving RAF officer but I think the time has come for him to fully embrace the firm and not opt out of what is not suitable for him. Harry´s visit to Lesotho is admirable but he shouldn´t forget that his first duty lies in the UK which also has a part of its population living in eceonomic misery. The York princesses are a case apart... somebody needs to ake a decision on whether or not they will be Royals or will not be Royal in which case I think they should renounce their HRH and Princess titles and disappear.
As history proves, every action brings reactions - and I suspect the palace takes a wider, more cautious view of things. They tend to practice patience and let things happen naturally - however slowly it appears to us on the outside.
There is the matter of volume and cost: the goal is to reduce the working royals, not increase them. There are already 12 elder royals on the royal circuit. Bringing the younger generation forward now will bring stronger calls for the elders to retire, and they may not be ready to do so. The Queen's cousins are of retirement age and starting to step back, but Andrew, Edward and Anne are still middle-age and have many more working years ahead of them. What else would they do?
There is also a matter of priority. Charles and Camilla are next on the throne, so the palace's first goal is to solidify Charles as the next monarch, not to mention continuing to best to position Camilla as an acceptable consort in the public view. Moving William forward now could actually hurt that objective.
There is also learning from past mistakes - letting Kate settle into her role slowly - and letting her add motherhood into the mix before she launches into full time royal duties - may prevent a repeat of recent royal marriage disasters. And it is pretty clear to all that Harry is still a wee bit too immature to be yet trusted as a full time public face of the British nation. He has a little more growing up to do first, and the military is a good training ground for a young man.
Looking at the whole picture, I think the palace's current plans are wise. Focus now on Charles and Camilla. When the current reign starts to wind down and the elder royals retire, then bring the younger ones forward. In the meantime, let the younger ones continue to mature and prepare. As to the York princesses, I've read that Andrew is lobbying for them to be working royals. Yet they are only given the occasional token duty to perform so far. I suspect the Queen is hedging her bets for now to keep the peace. But I also suspect once Charles has grandchildren to secure the succession into the next generation and he himself ascends the throne, the Yorks will be encouraged to pursue private lives. That is just guessing on my part, though.