The main consultant who worked on the ICG report on Sa'dah sent me this thoughtful response to my post earlier today:

Regarding the fact that the report considers the Saada conflict the most "deadly and dangerous", it is my own personal analysis, not what the government thinks. Deadly, undoubtedly: how many people have died in the South since the movements started? In Saada, although there are no trustworthy estimates, it might more or less be a hundred times more...

Dangerous in the sense that the South is in a way peripheral while if there is a spill-over of the Saada conflict with tribes in Amran fighting, groups in Marib, al-Jawf and Dhamar joining in, the heart of
the regime is touched and this can be really messy.

On the rehabilitation, you know better than I do how al-Hitar's communication was not always consistent. On turning the Huthis into a party, I agree that it would be difficult but we shouldn't underestimate the capacity of the group to evolve. Abd al-Malik has his own strategy, one that is different from Yahya's and different from Husayn's. So God knows what they might do: once again, I don't see it as a matter of ideology but more as a matter of political opportunities.