Plus isn't there a limit for newbies to how much they can post in a certain amount of time anyways?
Yes, there is.
The limit isn't only for newbies, because it's based on activity:
waittime = 360;
if(activity >= 15)
waittime = (int)(90 - activity);
if(activity >= 60)
waittime=(int)(34.7586 - (0.0793103 * activity));
if(activity >= 100)
waittime = max((int)(14-(activity/50)), 4);
In the case someone doesn't understand it, here is a good "translation" of the code above:
Its just activity, see the formula you linked. Its boild down to 3 basic steps:
the first major reduction to 75-30 seconds once your activity is over 14, but still not 60 or higher
the second reduction to 30-27 seconds once your activity is 60 or higher, but still not 100 or higher
the third reduction to 12-4 seconds once your activity is 100 or higher.
Once you reached 500 actitivty you will be stuck at a 4 second limit, which I notice once in a blue moon.