Not exactly an "easy" solution considering that all of that has to be added in manually, and ideally for every piece of content in the game. An XP system that doesn't revolve around murdering everything is a much more elegant and practical way of encouraging the player to make genuine roleplaying choices, although it's too bad that PoE makes a bit of a mess of it.
No it isnt, it just makes the player not feel particularly invested with the outcome, who gives a shit, its not a hard choice, just pick whatever and lets get this over with. You are talking out of your ass if you believe otherwise. Reactivity or rewards are the two only ways to make the player care, rewards should be handled according to what the player did, your idea of giving the same reward for everything undermines the entire idea of player agency. I find it disgusting and i find you disgusting for even proposing it, practical it isnt, as show by poe, elegant? maybe, i dont care about elegant shit, i care about shit that works, in this context your proposed system doesnt.
Shit, i didnt even pay attention to quest XP in poe, who gives a shit, you lvl when sawyer says so.
Raedric's Hold is a rare example of a quest which is genuinely improved by the lack of kill XP, as the alternative solutions (stealth, disguises, diplomacy) appear as viable or even preferable alternatives to a risky all-out assault, and there are some smaller quests where stealth is viable as well, but the vast majority of content seems to be designed with total slaughter in mind.
I didnt care, it didnt make a difference, i just murdertrampled everything, ending of the quest is basically the same for the player and those he cares about, nothing matters, you dont have anything to regret or to try in a future playthrough, you didnt miss anything, even if you did, who cares, you are swimming in copper and items are shit. while level design of raedrics keep is very good, the quest in itself is shit, no one but the priest cared to ask me why i was murdering everyone and the dialogue wasnt extensive enough to allow me to explain my reasons to anyone, but who cares, its not like im playing an actual rpg, is it? Everyone kept charging at me to get murdered, it all blends together in a pool of blood and agony, who gives a shit, its over fast. I even murdered koescl or whatever that cucks name was, i didnt even knew the bastard and he thought i did it for him. Goddamn retarded.
The priest and the witch talking you into killing the other was nice i guess, i just murdered the witch because i didnt want to have one more loading screen after killing the priest, the reward didnt seem that hot to me, wasnt planing on having children, and i figured the endless lore dumps would make sure to inform me just why the fuck the hollowborn existed, i didnt need the witch, the game was too eager to tell me everything about it anyway. The priest was really grateful that i saved that kid. I probably murdered everyone he ever knew and cherished, and was covered in their blood as i talked to him, he didnt seem to mind, maybe if he got angry next time i would have tried to stealth or disguise my way there, but nope, sawyer wont deny you a quest just because it makes sense, you have to actively screw up knowing all the info for him to do so.
The half-assed mechanics, like infinite stash and partial kill XP, only reinforce that kind of thinking. Every xaurip isn't necessarily free XP, but it is free money, and that usually is a good enough reason to stick it with a sword. Many dungeons do let you make a beeline for the end boss by picking a lock or two rather than having to look for a key, which is nice, but if that means that you'll miss out on 90% of the dungeon and probably some interesting content in the way, it's probably not that satisfying in the end.
Its just easier to kill everyone and loot everything, combat is over fast, it isnt hard and hey, you are playing a game, why would you actively avoid playing the fucking game? Combat isnt THAT awful that id rather spend an extra half an hour not fighting to get a dungeon over with. Stealth was a expensive inclusion that brought next to nothing to the table.
Could you on your inevitable answer post some examples of games that successfully did away with combat xp in favor of quest? Dont just pull it out of your ass, show me something. And dont bring irrelevant examples like SSR or VtMB.