1. Currently there is one companion more. It is unlocked through the right Perk Tree and after unlocked appears in each run and can be recruited. The perk also is star shaped so its easy to spot.
2. Is kind of a puzzle where you need to think outside of the box. For a hint: You need to have unlocked the blacksmith fields from the right perk tree and artefact smuggler from achievment unlocks. It is a more late game thing.