I did search i couldn't find the answer to my questions.
So I wanted to know:
- On this server, to do those combo taekwon moves, do you have to be in the top 10 taekwon ranking?
- And which would be better; to change to a Star Gladiator and keep using the taekwon skills or just stick in being a taekwon kid and not job advance at all?
- Also are TK/Star Gladiator's any good in PvP and WoE?
Thanks 
First, yes, you have to be a ranker to combo your kicks.
Second, if you want to continue to be a ranker, you either better get a whole lot of points and then change into a SG, or stay a TK.
Third, if you are a well equiped ranker, you can be effective in PvP and WoE. a Garm Glittering Jacket is the best armor you can wear, and DL boots/sleips is the way to go for footgear. Everything else is really up to you.
Also, Ranker TKs above level 90 also get a 3xMHP/3xMSP bonus and have all their skills unlocked and maxed.