+1. That should work here. It could be useful. Auto lock isn't a good idea but choosing the 'Best answer' is a good idea.
If "like" system gets implemented to the new forum software, i don't think we need a "Best Answer" cause people will be aware of the likes that a post received, so literally; highest like = best post and vice versa.
Not practically. 'Like' can be misused with alts though we can understand depend on that but not all time. And 'like' is enough, 'Dislike' is not a good thing here.
-MZ