Hi! First off I would like to say welcome to fRo and I am sorry for any inconvience you are having with our classes but I assure you we are very balanced when it comes to PvP and I will explain why.
- As you stated for the creator class. Creators currently are very powerful. They can stun lock player with Acid Demo for it is highly spammable here. You stated we have the easily obtainable Ghostring card which is true but it does not make Creators miss it only reduces the amount of damage they do which in turn creators can use their L.Weap/Jorg/Fireblend to bolt them. The trick to Creators is to ruse the opponent into switching armors/cloaks so you do respectable damage.
- Gunslingers with their skills. A lot of players overlook the utility of all of their skills when it comes to Gunslingers but that still doesn't diminish their power in PvP. Gunslingers can use Rapid Fire to create loads of damage on an opponent and when they penuma the Gunslinger can use Desperado. In combination with the Assassin Cross card Gunslingers are a force to be feared.
-The immunity to freeze is something that balances out other classes, as well as Wizards. Wizards excel using AoE magic spells, that is what makes them terrifying. If we didn't have the immunity to freeze Champions would be completely overpowered. A frozen asura is not a fun asura.
-As for priests go, it is a class that is overlooked. But iirc I see 2 priests actively playing on the server currently (MARV3L and Adorable) I am not too sure how well they do in pvp but I see them playing quite a bit so the class isn't totally forgotten. Ever since their holy light skill was nerfed in terms of being spammable their 1v1 potential has decreased but they still play a great support role.
-Stalkers have their Copy skill which makes them versatile as well as their Stalk ability that outranks Cloak. They are a great class to play as. Plus their strip isn't relied on autoattacking.
-As for TKs having a L.Weap, they do more damage without a weapon equipped. Try it out sometime, I'm sure you won't be disappointed. :)
As for the server as a whole I believe we are very balanced, you just haven't had the chance to try out all of the classes on equal ground, because like you said you have only been here for 3 weeks.