Razzle I use invis, along with two of my RL friends to 'cheese' our way through the Orc fort in SS all the way to Premus and Kruurgal. We only stopped maybe twice inside the tunnels to wait for the 'see invis' dog to path by, killed it and continued to 'cheese' our way in with invis and SoW, skipping a lot of content. We managed to get the 2H sword from Premus and three heads from Kruurgal for the SS earring quest.
By your definition, invis should be removed too. I don't mean to be argumentative, but there's only so much you can remove from the game to combat player innovation before you make the game very tedious and boring. We are all busy adults; we save time by moving in and completing what we came for. Skipping trash isn't breaking the game; breaking the actual boss camp is where the fun is. Removing those clever shortcuts doesn't make the game harder or more prestigious—it just drains the time of busy adults who only have a couple of hours a day/week to play. After reading here ,some cultist will tell me this game is not suitable for me and go play other games. However we did spent a lot of time scouting and dying/Cr while learning the zone. On the 3rd time, we started to just invis/sow and run to save time
Anyway An Elementalist definitely won't be able to solo in invis and then CotH his friends to Kruurgal.
They know they can't remove invis and SoW, even though these two spells allow players to skip content, because there would be an uproar since it affects so many classes. But they can remove CotH because there are only so many Ele around, and maybe even fewer now with the rework.
Nice talking to you although we have differing opinions.