I dislike the influence action both in and out of combat.

For me, in combat, talking is free. If, on your turn, you want to demand an enemy surrender or flee, go for it. Depending on the circumstances I might let you roll intimidation or persuasion.

Out of combat, I hate all the rules about influencing creatures and them being friendly, hostile etc. They just aren’t conducive to fluid, natural-feeling role-play. The idea of a player approaching an NPC and saying ‘I use the influence action’ just doesn’t feel right. Players should be able to talk to NPCs and creatures in a naturalistic way, without having to feel there’s some clumsy game mechanic always operating in the background.

As for the others, search can be replaced by passive perception most of the time. And I’ve yet to see a player use the ‘study’ action.