Ok well this look's like a total FAKE ....BUT :
The things that he told ya about ppl got stuck in Roc Mountain and they are brazilian is a pure joke,or he was messing with you.
When it comes to turks accounts,it could be real,think about it,if the GM is an ex player who was scammed by a turk or one good friend of his or some ppl from his team,wtv,they could have some reasons to hate turks,since is a private server they make the rules...
About the 5x for european and 3x(or 2x O.o) for chinese is one simply logical explanation:
The europeans may have cap 100 but skills limited to 70 or 80 or who knows but 100% they don't have skills 100,so against the chinese who have cap 100 and skills 100 would be a little bit unbalanced,I realy dunno how a lvl 100 lets say warrior/cleric could beat a lvl 100 archer with skills 100.So because of that,maybe they are putting these limits.
The fact that from 30x we are going to 5x and less could be because now the party mobs appeared and you can lvl so easy in a party and can farm even more better.
These could be some true info from a funny mouth BUT we still have to see it with our own eyes,aren't we ?