Drafts (Connect’s feature) are saved as long as you don’t leave a thread.
Individual upvotes and downvotes aren’t shown on Lemmy as a whole. I only know you can see them under posts and comments on kbin.social (another network), but I don’t know if they have them collected somewhere on a profile page. Guess it puts more strain on servers hosted by volonteurs.
Visited posts are tracked cleint-side. Afaik it isn’t implemented anywhere.