I strongly suggest the hot topic feature not be by number of posts in a topic. Many forums have "Hot topics" that are 2-3 forum members arguing back and forth.

I say that posts that get lots of likes in the OP should be used for Hot Topics as to foster people to click on posts that may be off the front page but strongly supported by the community.

Promoting big post topics will not do the community any good and just embolden the current trolls to make more arguementative posts just to garner high post counts.