I saw your email this morning. I decided to answer here since others might have the same question.
To find somebody, there's a couple of ways. The first is to just go to your own Fantasy page and scroll down through the Leaderboard. Keep in mind that the Leaderboard defaults to 2008, so you'll need to reset it to 2021 or whatever year you want in order to find the top performers.
However, that takes forever to do if the member isn't up near the top, so there's a quicker way. Do a search for any posting made by them. Then click on the small chart icon in their post (look in the upper right hand corner of the post, it's the left-most icon next to the pencil). This will take you to their Fantasy page. They will be the first one listed on the Leaderboard, and to add them to your own watchlist you click on the small eye icon next to their last IFT date. The icon should turn blue, indicating that the member is now on your watchlist.
To remove somebody from your watchlist, just go to your watchlist and click on the blue eye icon, which should turn it grey. Refresh the screen, and they should disappear off your list.
Recommended Reading: http://tspcenter.com/forums/viewtopic.php?f=14&t=13474
"It's not what happens to you, but how you react to it that matters" Epictetus