Hi James. Thanks for the work you are doing to help us little fish. I appreciate you.
so do not upvote a post that is past payout. You can comment on any post to see if they would respond to comments, and thereby upvote on the comments for some kind of recognition.
I have been upvoting many posts even though i notice they are past thier sell by date, thinking that even though the author wont get and steem reward for my vote, it would still help thier post rank higher in some algorithm somewhere therefore getting more attention. Am i wrong in this assumption?
Yes since they do not receive anything that you upvote with. It is best to leave them a comment, and if they respond to it that can be voted on to give them an upvote and a reward on that comment, that they will receive.