HiG has declared in the Exp. 11 rules that there are no official rules when combining it with other expansions, major or minor. This seems to have created some response from some fans in the comunity, as you can see in the following ongoing discussion on Reddit started by u/threelonmusketeers, a fellow fan and member of the community:
https://www.reddit.com/r/Carcassonne/comments/xdldt0/ghostly_questions/Here you are his initial list of questions:
Exp. 2 - Traders & Builders* Are pigs or builders afraid of ghosts?
Exp. 3 - The Princess & the Dragon* Are ghosts on the dragon's menu or diet plan?
* Is the dragon afraid of ghosts?
* Can ghosts haunt the fairy?
* Does the fairy provide protection from ghosts?
Exp. 4 - The Tower* Can ghosts haunt a meeple on a tower?
* Can ghosts haunt a captured meeple?
* Can a guard meeple be placed on a tower?
* Can ghosts be captured by a tower?
Exp. 5 - Abbey & Mayor* If a wagon moves, do ghosts follow?
Exp. 6 - Count, King & Robber* Can ghosts haunt meeples in the city of Carcassonne?
Exp. 7 - The Catapult* Can ghosts be removed by catapult knock out tokens?
* Can a player exchange a regular meeple for a guard meeple via seduction? If so, what happens to any ghosts that were previously assigned to that meeple?
Exp. 8 - Bridges, Castles & Bazaars* Can ghosts haunt a meeple in a castle?
Exp. 9 - Hills & Sheep* Are shepherds afraid of ghosts?
* Are sheep afraid of ghosts?
Exp. 10 - Under the Big Top* Are big top animals afraid of ghosts?
* Can a guard meeple participate in an acrobat pyramid? If so, is the entire pyramid protected from ghosts?
Miscellanous* Is the phantom afraid of ghosts?
* If a meeple gets trapped by Vodyanoy or Solovei Razboynik, do the ghosts follow?
* Can a meeple trapped by Vodyanoy or Solovei Razboynik be retrieved via the addition of ghosts?
* Can ghosts haunt the Teacher?
* Can ghosts haunt the Wheel of Fortune?
* If a haunted knight escapes a besieged city, are the ghosts returned to the supply?
* How do ghosts affect scoring of the "Cash Out" gift?
* Can ghosts haunt a meeple in a bathhouse?
* Can a regular meeple be swapped for a guard meeple via La Porxada? If so, what happens to any ghosts that were previously assigned to the regular meeple?
* If a meeple flees the plague, do the ghosts follow?
* Can ghosts haunt the Mage or Witch?
* Can ghosts haunt the Gingerbread Man?
Any thoughts?