If they’re going to be added, they should definitely not be added to the comments. That would clutter it up way too much. If they are added to posts, a line break between the post itself and the signature would help along with making the font a lighter shade of grey. Not so light that you cannot read, but something like the date and time next to the comment’s name (about 50% grey? Can’t honestly tell. I want to say 40% but that might be too light). It might also be aesthetically pleasing to place it in italics. That way those people who don’t really want to see it automatically see the slanted, light font and skip over it, but it’s available to someone who does want to read it.
If they’re going to be added, they should definitely not be added to the comments. That would clutter it up way too much. If they are added to posts, a line break between the post itself and the signature would help along with making the font a lighter shade of grey. Not so light that you cannot read, but something like the date and time next to the comment’s name (about 50% grey? Can’t honestly tell. I want to say 40% but that might be too light). It might also be aesthetically pleasing to place it in italics. That way those people who don’t really want to see it automatically see the slanted, light font and skip over it, but it’s available to someone who does want to read it.