I'll be honest, Farah Khan isn't a good director. But as long as she succeeds in making an entertaining film (forget TMK by entertainment I mean OSO), the film is destined to become a big blockbuster. Even OSO was not the great content wise but it was bang on when it comes to entertainment & that's her forte. Srk is sporting what you can call his best look of recent times, an ensemble cast who really know to act so if Farah doesn't get carried away like TMK, Blockbuster is the minimum verdict the film will be getting.
The prediction part I'll be omitting. By the time HNY releases the business would've escalated further more, the screen count will increased since Kick will be the previous big film which would be getting maximum screen space so HNY most probably will get screens in the range of Kick or even more since it's a solo release. 275 or 300 are unrealistic, let the box office play it's game & let's all bother about the entertainment the movie promises to provide. Diwali for Srk is like what Eid is to Salman or Christmas is to Aamir. I hope it'll be a treat for family audience like his CE was.