So finally, I am giving out this long awaited draft:
It addresses some of the OpenType, Unicode and fonts related issues. Many of the issues discussed here, have been the source of conflicts, especially for ml_IN. Thus it was an utter need to provide a detailed analysis like this. I hope the illustrations made there provide some common guidelines. There is certainly a scope for improvement. I would like to hear from various communities if they want some of the other left out issues to be also addressed.
The draft is open for discussion and feedback.