Very good questions!
Firstly, excuse me if I'm a little rusty with my own rules, as I published this a few years ago now.
Secondly, I strongly encourage you to make the game your own at the table. Bend and twist and interpret and create rules as you see fit.
That being said, here's some answers for your questions:
- Each action starts with zero dice, so...
- ...If you make a roll with no Traits or Clues or Collaboration, you will have zero dice. I think the "(or less)" is probably a relic of an earlier draft which still had Conditions.
- It is phrased fairly ambiguously, but I think you're right. I, personally, prefer to restrict myself to very sensible theories, but that rule's probably there so Consultants can just make absurd and silly connections and be awesome.
- Yes, it is entirely possible and intended! I find Carved From Brindlewood clues a little too lose, so I like to have like 2-3 different interpretations in mind when writing lists of clues. The main reason I made the Fabricate move is that I disliked being restricted to a list of existing clues in Carved From Brindlewood games and wanted players to feel free to invent their own mystery if they want. Because writing new clues is fun.
If you end up running it, I hope you have a bunch of fun with it!