In short. Yes, dont know, No and No
Rule supplement will defiently coming, it just takes time.
Well, there are two types of expansion. "small" and "big" ones. First big expansion was Forcemaster vs. Warlord and first small was Conquest of Kumanjaro. In small expansions, there is always (so far) alternative mage for already existing one. Now, in FiF, there was a wizard female planned for it. Arcane school is already good on its own so AW decided to change everything. And by everything i mean EVERYTHING! So from Wizard vs Warlock, they decide that Warlord deserve a boost and a whole concept of a small expansion was also changed. Now we have big expansions and big expansions with completly new mages. Warlock as an alternative mage stays in the box but thanks to a new concept, she recieved are those cool new spells so she is unique and you are able to play her fully and in a different way then male warlock.
This leads to Priest/Priestess problem. If Conquest of Kumanjaro was released in a same manner and a way of a concept as FiF, you would probably had no problem. There will be two great boosts for holy school in a future. Paladin vs Siren (big expansion with new mages) and cards from Mage Wars: Academy. And i can guarantee you, if from all those briliant cards at least one will be in a final box, you will be massivly satisfied
Elementalist. You are definetly not alone... yet i am looking foward to Monk or Barbarian mage