The current like system is already abusable (Margen "like bombing" people, for instance). Realistically, I don't think it would negatively impact anyone significantly enough to be a problem
because using a yeah is more so giving agreance to something rather than saying you like it, you wouldn't like a car accident would you, you would nod yeah in agreement with the grievances with everyone else
I wish the featured posts thing was brought back, but fixed, so it doesn't slow down the site and people can't "featured-wank". It was a neat thing IMO.