i miss (omg suddenly i can write :D) boats, wolves, heine, goddard and its hunting zones, MoS.. and for skills: old totem/rage mechanics cause they all were trade-ofs, they all had a purpose (not one totem being just sa superior version of the older one), old evasion mechanics, debuff landing was more complex (based on parameters and stats, tho that i understand its hard to calculate and balance right) and newer debuff mechanic that altough i didnt play god i readed that they implemented something to protect ppl from cc lock against same kind of debuff
about mental on oly i dont agree cause switch / trick efectivness is greatly affected by it.. but if it was up to me to make 1 custom change, implementing the same mechanic that sleep and roots have on fear, would make fear a skill you have to time right giving sometimes to enemy a little bit of time to react instead of brainless spamming..even if you play da horrible. if you lock him with 1 fear, its pretty much over if you just hold that button on and hit.. in the other hand if fear was like sleep, you could only get perma cc if the user is really good at timing it in the right moment.. i dont say the same for stun f.e cause there are already many ways to protect against it and also cause its not unbreakable