Removing Friends through the app (instead of through the web site) works a little better. Doing it through the app removes the (former) friend's icon from your Friends List on the web site as well. That's not always the case if you remove the friend through the web site.
To the OP - you seem to have added quite a few friends the last 3 month or so - many per day, in fact. Seems unusual. Not judging, just an observation.