I have previously asked about a way to learn abilities and gain knowledge without killing creatures, and one of my suggestions was a passive learning system, where just being in proximity to the creature let you learn. Someone replied that this would promote passive play, allowing players to gain knowledge without doing any 'work', and while I dont really understand why anyone would want to just sit there instead of fighting the thing, I agree there would be problems.
My new suggestion is that there could be action skills/abilities that work like the combat skills in that you have to 'engage' the creature and actively use skills while they attack you, only that these skills don't harm the creature, perhaps it could be that you 'tame' or 'capture' that particular creature rather than kill it to receive your knowledge.
This would ensure that any player not specifically intent on not killing, would simply fight it the normal way, as the end result is the same (except for the livelihood of the creature) and killing it will allow you to loot it, not to mention it would probably be faster and you would take less damage.
Additional to this, I Would like to ask about something I am sure I read, but naturally can't find any more, something about creature reaction to players being affected by previous interaction with them; ie: if you dont kill bears, eventually they wont attack you, or something.
I would like to ask if this is still planned? and if not, perhaps it could be the final result of my suggested Non-combat system: once a player has fully learned about a creature, without killing them, that creature type will only attack that player if the player attacks them. Obviously this would only apply to some types; 'beasts' like bears, spiders and so on as well as intelligent creatures/ elementals like goblins, trolls, treants etc.
Of course, part of the difficulty of certain areas is fighting your way to them, so this might still seem like cheating if you can just run past enemies, but I know a lot of players do that anyway to reach the harder areas they are going to, and most of the time players have done everything they want to do in an area long before they have gained full knowledge of a creature.
The Undead are obviously out of this idea, and the Legends are presumably not interested in being friends with such tiny pests as we are, and potentially, for example, shadow goblins are too 'monstrous', and so on.
Elementals perhaps could be aggroed by doing whatever they don't like, for example, a Treant seeing you cut down a tree will attack you, or really any primordial/elemental will take exception to the 'despoiling' of the land.
While a pacifist way to complete your knowledge could be interesting, I fear that it is one of those features that we will never see.
The reason is that as you correctly identified, it would interest a very small amount of players. At the same time, it is quite a major feature, which requires a lot of work and testing to be added to the game.
This game isn't being developed by thousand of people, so we can't expect features which fall into the "Nice to have" category. Especially if they are complex to implement.
I do expect there to be something similar for beasts and tamers, but you are always going to kill goblins, elementals and similar.
I remember there being a taming system proposed by the developers.
Presumably if you tame a creature it could increase you knowledge of the creature and thus give you KP.
That right there could be your non violent knowledge method.