Yeah a lot of people dont know they can change class, and, they can change class once ingame and they still get exp for the queued class now.
I can only say you how it is atm, I would like to see differences between small and big pvp modes too, but devs have the opinion that they wanna keep it easy to learn - and 2 different sets of additionals in PvP might already confuse people. The same people who can do pretty well with 50-60 Logos actions for an exclusive eureka mode or with bluemage with 50 skills.
Regarding healer, if there are 2 many, they gonna lack in damage, you have to try to focus one after another down and make them use their stuff or you take the objective so you get points and they can just heal themselves and be useless.

The problem in the past was, if you only have 9 personal job skills to balance it out, you can be overdoing it very fast and its unbalanced again. You could ask why gnb and darkknight dont have their invulnerabiliy, drk used to have it in old pvp. You could even cleanse yourself with purify the livingdead zombie debuff, was some high IQ play.