>>/1/
Agree with you on insider, mine are.
problematic (because tumblr)
SJW (because Overspammed)
cuck (same as above)
newfag (when being spammed by LARPing newfags)
reddit (both do to all the hipsters at that site and the idiots who think that everything they don't like is reddit)
normie (feels like a butthurt incel when used, use normfag when derogatory or some phrase like mainstream average person otherwise)
slash/het (old fandom terms I don't see as often in the newer fandoms but I still hated having to deal with those crazier shippers and their bingo boards) 
I would include 'lit' being used as word similar to 'cool' but if that helps that word survive against 'lighted' than I'm all for it being used among the younger population.