The sort of feedback I'm currently most appreciating is of the kind you gave: Both high level comments about the concept and how it reads when you don't know where this comes from, and specific comments on the particular particular moves, i.e. mostly the two of
Your spirit comes from a different time and knows things that most people now would not. When examining or confronted with something from a different reality, ask the MC three questions about it from the following list and roll +weird.
• What use or function does it have?
• How do I work it?
• How can I fix/break it?
• How powerful does it make someone who can use it?
•What part of it is most valuable to sell if it can’t be used as intended?
On a hit, you get useful answers, but your spirit demands something in return. On a 10+ choose 1, on a 7–9 choose both:
• if you do it, you mark experience
• if you back out, it’s acting under fire.
and
When rolling to help or interfere with someone, roll as if you were making the move yourself, instead of +Hx. On a hit, they take +2 (help) or -3 (interfere) to their roll, instead of the usual modifiers.
because, as mentioned, a probable application of this playbook is to switch to it, gaining in particular two moves similar to these.
The idea behind the playbook is that of someone in possession of a particular item that has a spirit, personality or something attached to it, which has taken some form of possession of the owner. How much the relationship is symbiotic vs. antagonistic, and how reversible/exorcisable it is, I would prefer to leave open, but if you think it doesn't work being both, that's not necessary, and should be cooperation at a price. (The examples of things we thought of are Harry Potter's Tom's Diary, Harry Dresden's Bob, Antimony Carver's Reynardine, Herbie the Beetle, Aladdin's Lamp, Em's Dybbuk Box; Admittedly in none of these cases, the spirit somehow merged with the owner, as is the case with Rothschild who prompted this idea. More suggestions for fiction to look into are welcome.)
Essentially, I would also like to take some inspiration from the Faceless. While the Possessed with his Thing is about having an otherworldly connection, where the Faceless with his mask is so fucking hard a Hardholder might cower away, stuff like the Faceless' Norman and As One should still be valuable as inspiration.
Questions of “Spirit of Intellect” are indeed still quite close to “Things Speak”. (It started out from the Coot's “Remembering the Time Before”, actually). I just changed the “price” one to “How powerful does it make someone who can use it?”, but I'll have to think of some better-fitting questions, and then see which ones to keep.
The intended difference between “Spirit of Intellect” and the likes of “Things Speak” is that you get a lot of answers, maybe even on a miss (“On a miss, you may still be able to exchange promises for answers, but maybe the answers are just what your spirit wants you to think.”?), but the spirit will demand something in return. Unless with a good idea of something “Norman”-like or the Synthetic's Sentience Clock, I thought this might be at least a mediocre idea to get the spirit's agenda forward, and should then be a move you have to take.
Also, yep, this does not work on every thing in the post-apocalypse, and while, as I currently word it, it should work on anything non-post-apocalyptic, it is indeed a significant weakness that there is no implication as to why a 20th century documentary film maker mind should know anything about psychic maelstrom mutants or future antigravity tech. Thanks for pointing that out, I'll have to think about how to fix it.