I have seen a lot of threads, mainly complaint about pvp and the new schools. While some of these discussions are healthy most of these are just mere rants. From what I have read a lot of these are just fair play concerns. With the addition of new game mechanics the list of things to complain about goes on and on. Well I have played a few MMO's back in the day when the genre was still at its early stages. The thing I have noticed is that for the majority of these early MMO's the fairness of gameplay esp. in pvp was not a common issue. Seems those developers mastered the art.
Now my suggestions or solutions if you will. The top most priority is hire a mathematician. Not just any math genius, look for people with experience with Dungeons and Dragons the pen and paper era, people who have worked with Trading Card Games and real time strategy gaming. With the aforementioned fields of gaming the games usually start out unbalanced but with proper calculations and countless replays they are able to tweak mechanics to improve overall game balance, the last thing you should be looking at is people's rants. By looking at a problem subjectively you will come up with literally millions of ways to solve it, but if you change the perspective and look at the game objectively (come up with formulas to determine this) you can come up with maybe the same ways to solve it but with more quantifiable solutions. Some people can argue with it but that is the beauty of this you can tell them just look at the math it all adds up.
Lastly this is more of my own opinion. Compartmentalize. Do not try to find an all around solution for every problem. With pvp for example try to divide the players who can enter the arena. A room for people level 1-9 then 10-19 etc. just divide it in a way that before people can get the gear for the specific level so that there is no big advantage over other peoples level. The game being a trading card game format, it is also important to divide pvp in such a way a normal TCG does it. There would be deck types. For example a type 1 deck would only allow people with normal spells and treasure cards without the astral spells. type 2 deck would be a no polymorphing deck and a deck type where everything is allowed. That would force people to play fair and still play on the style that they want. Pets should also be accounted for in this situation as they should be considered gear. BTW your current automatic pairing is just epic failure.
I just started out playing this game for almost two months while I really enjoy it there are things keeping me from staying. My friends and I started playing and I am the only one left, they decided not to continue anymore.