First, a fresh install of vanilla freebsd using 700mb ram is impossible.
The only reason why that would happen is due to third party software.
Most (bad, just ignore them) providers will provide you with a freebsd vps with pre-installed software. You just manually install freebsd in those cases, as you should do anyway.
Regarding the "USB / CAMERA", you are reading topics from 2012 where people built their own kernels stripping them, for absolutely no reason whatsoever, as it has 0% performance impact in the real world. You maybe save what, 20MB disk size....? A metin2 syslog easilly takes more then that.
Just install MANUALLY your freebsd without selecing services that you wont need.
Then if you want performance increases work on your metin2 source, because thats where the crap performance comes from, not from a rock-solid OS like freebsd.