Ha ha dont worry about the ticking off for double posting, its not a good idea to do that but doing it by mistake can happen to anyone
The G's is G force, and can not be set directly by the user, it is as you suspect a result of your acceleration.
Dir and Step pulse shouldnt really make too much of a difference, well having it too low for your setup can be bad but having it up to its max of 15 or whatever likely will not have any ill effects unless your kernel is very high. Talking of kernel, you should not have that set to any higher than you need for motor tuning as that can be detrimental.
As it is servos it could be a problem with the tuning in the servo drives or could even be a weak power supply, ie when using multiple axis the supply doesnt have enough capacity.
Hood