What exactly would a five post limit accomplish? What if he's in a game blog and decided he really wanted to talk basketball? Farfetched but let's say he's behaving himself and posting properly? Does he still deserve to be banned after post 6?
The point of the 10 minute limit is to prevent him from being able to go on his parroting sprees. If he has to wait 10 minutes then the hope is he'll give up on parroting or, if he decides to continue parroting, it's been extremely hampered.
The system isn't perfect and I've already received PM's outlining ways he might get around it. If he does that then maybe your proposal should be taken more seriously.
And

at acting like HarlemHeat gives a about this. Of course he's going to toss your salad on this subject, you don't agree with me on it.