How are you replicating keys to your second client? As Mirai points out, you need to pass SOMETHING to the other client in order for it to do things. EMA follow strobing is the only thing I can think of where that's the exception, but things like casting spells, etc...I just don't see how it's accomplishable otherwise.

In order to interact with a target (AKA talk to a quest giver), you need to pass a keybind that is bound to your "Interact With Target" keybind in game. There's no way around it, you cannot macro that action in game.