I managed to increase weapons levels, once increasing them over the max, the game will never load anymore.
Tried on different accounts, managed to max a weapon, refreshed, value became normal.
It seems the Kill-Count can be hacked, someone has a large number of kill-count, a number thats only hackable.
If Kill-Count can be hacked as it seems, then the exp-gain should be increasing together with kill-count.
I gave up trying more, most of the stuff is 4bytes, exp is float.
Exp is not directly hackable, the value reverts back to normal.
To be able to change exp, you have to know the TOTAL amount fo EXP your account has.
I found it by a longsearch, started with unknown initial value then i killed some people to gain exp.
I then made an exact search by " increased value by xxx " (xxx is the exp i gained through the kill).
After a long scan, i found out that at lv.28 or 29 my total exp was like 170k something.
Changed it but no effect.
I hope someone with good knowledge can make some hacks for this :)