Hi Avinash,
I think I saw in the last rules you posted that you would prevent all PMs unless from moderators or admins. The only thing I would see difficult is that sometimes users will communicate their email addresses and such through PM as not to post it directly on the site and In my opinion this rule may turn many users off to using the forum as PM'ing is a big part of communication and reserved for things that don't belong in the public forum. I badly worded my PM posting suggestion as well. I meant no posting a PM into the public forum but once again, worded it badly. Of course it's up to you and I am only hoping to give some feedback or suggestions from my opinion and in no way trying to go against your decision m8.