Nonsensical suggestions and overhyped problem. They are allowed to participate in any debate here, and 'butt in to conversations', when you post on the forum, anyone can quote you and respond. And how exactly have Indians taken over PDF? All mods are Pakistani, management is Pakistani, the rules and restrictions on postings have a Pakistani leaning beyond a reasonable doubt. Yes we have quite a few Indian members, and not all of them are quality posters, some are trolls, but so are plenty of Pakistanis.
The current system penalizes breach of forum rules and decorum, and filter certain speech (largely any bias here is already Pakistani). What you're suggestion is destructively disproportionate and a sure way to harm the forum and destroy the opposing view, which is necessary for any debate.