Last activity and a (small) icon are valuable information. The icons visually distinguish users and "last seen" lets you know whether you are replying to a per

Last activity and a (small) icon are valuable information. The icons visually distinguish users and "last seen" lets you know whether you are replying to a person or primarily replying for the benefit of the community. Also, distinct pagination means you have a stable location for each post instead of "scroll around until you see it". I agree with your point about signatures and initial sign-up being clutter.