Track own actions on the site (and possible actions of others?)

A user should easily be able to see the list of his/her own proposals and all proposals that he/she has taken action on, e.g. commented or recommended them. I know its possible to get these on a raw Excel sheet but this is not very user-friendly. We have got several emails from people who cannot find their own proposal on the site, because they have forgotten its title and cannot search it up. Based on the feedback we have received, users would also like to browse the actions of other users (some have suggested searching proposals by username; others have suggested a public news feed connected each user profile, like in social media).