You don't have to let a comment stay to receive "credit" for the engagement. I definately was not going to allow the one who was using foul language against other commenters stay around anyway.Replies are engagement, so they actually help you.
If you don't feel negative about the comments, let them stay for your benefit
A couple of mouse clicks and a minute of typing should not qualify as effort at allYou're putting too much effort to look into their profiles before you reply them, if I was a troll I would consider that as a win for myself cause I made you use real effort to check my profile AND respond to me.
But then it could be that you are having fun responding to them, so proceed!