It seems to me that there should be different Activity Vocabulary object types for individual thoughts and reasoned discourse. This would allow for filtering and sorting and grouping such that a timeline would naturally say "person X had a series of thoughts recently" as one item in the UI, rather than scattering them through the arrival of edited texts. It could also specify that a Thought, unlike a Note, can't link to anything (and so can't be a reply), so you can scream, but you can't scream about anything or at anyone (in a way that links to the target), and if someone wants to respond or you want to explain, it has to be in a ~paragraph Note.