If the plan is strictly getting Steem then I can see how unfollowing those who don't upvote your comments can be beneficial BUT I don't think its a wise move over-all.
While getting upvotes is the main goal, getting comments and interacting is also important. When you comment on someone else's blog it isn't just the blog owner that sees your comment. Their followers also see it and while they may not upvoted your specific comment the odd one may click your profile to see what you have posted.
My goal has been bringing my average to 1 Steem a day over the past 100 days and I need 20 Steem to accomplish that in the next 10 days so its looking like I will come close but ultimately likely to fail.
Also @dustsweeper is only averaging 2 votes a day on accounts due to being over worked so any current rewards given under the threshold is likely wasting VP and rewards.
I think the people who actually upvote you are more likely to follow you.
Sure I think that's true.
Using myself as an example .... me following an account means very little as I manually type in the names of the blogs I want to visit. If I am not mistaken I visited your blog for months until one random day I noticed I wasn't following you and then did so.
I rarely visit my feed but I try to make a point of doing so once a week and give out random upvotes. I normally mostly just visit the blogs of those who are being active on mine regardless of if I follow them or not.
I would love to see Steemit add a Favorites option to go along side the followers option. That is a feature I think many would find handy.
Scratch that I only need 10 Steem as I forgot to add in my liquid Steem so I will be cutting it very close to 1 Steem a day on average over the past 100 days.