Mind Reading. This idea would require a LOT of text, but very little actual programming or new systems, but the ability to read minds using Thought Control. For most random people this would be random text, possibly humorous, or giving background. Like, you read someone's mind, and it's mostly useless, but interesting info about their lives or love interests, drug additions, crimes, worries, etc. But for other people, maybe you need to get info from someone and your skills aren't high enough to persuade them (or they simply can't be persuaded) you read their mind. This method could be used to get safe/door codes, key locations, item and stash locations, learn of waiting ambushes, but it's kind of a gamble, because you might not get any useful info, but would still spend your psi points. (Perhaps a higher cost if the info is more valuable?) I'm thinking something similar to Divinity 2. It's a very balanced system, just might not be easily implemented.
Basically, you have a list of generic text, could be anywhere between 50-500 lines (depends on how big the game is, and how many NPC's there are) and that's the generic stuff that will be given to random NPC's you can talk to, but don't really need to. It really depends on if the ability is accessed through dialogue or if it's a point and click ability. If the former, then it'll be a lot easier, as you can only use it on npc's you can engage in conversation, but the latter would require more lines (nearing the 500) to give to EVERY visible npc.
Anyway, then every time an important npc is created, or in general any npc with useful information (that doesn't require a huge quest to get) you don't give him any of the generic dialogue, but rather that important bit of info.
Obviously there can be a static check, perhaps your TC skill level to their will, or something, that determines if you can actually invade their mind or not, and the better the info or the stronger the will, the harder that check will be to meet. A message saying their will is too strong, or something, could pop up, and you know you need to simply find another way, or up your skill first.
This is a system you could put in that would not change the existing game by too much, and would provide interesting alternative ways to get information.