Very good points. It is easy to get tempted to downvote someone who upset you by downvoting your stuff.
I, myself choose my upvotes carefully now. I stopped upvoting whales posts a while ago. Now I choose what to upvote and don't just jump on post becasue it was posted by some whale. I carefully spend up to 8-9 maximum votes a day on posts of people whose posts I like or consider worthy of the recognition, despite that my little SP gives little SD reward yet. I, also often reciprocate upvotes on my posts. I like to give back when others share with me.