I don't use other social media to distribute my articles or any of Fellowship Writer's stories. I tried doing that when I first joined Medium, but I didn't find it useful.
To this date, I've found 1 advantage of having non-medium readers view your stories, and that is you will get a percentage of their first-month dues - if they decide to join.
Non-Medium Members get 5 frees stories per month. Their views contribute to your stats in "exterior views," but again, not to your earnings unless they join.
Unfortunately, you cannot auto-clap 50 for stories, at least that I know of. Also, if you clap too much like me, your claps start to lag...
When I'm adding followers, I look up famous writers who have 10s of thousands of followers and go through their list.
Hope this helps!