Paranormal stuff-Will they nerf it?

Yeah, I can't imagine it in this case either. Other features that people have complained about for being too intrusive, such as alien abductions and vampires breaking in, were things that just happened, whether you wanted them to or not. But this pack's ghost business is something you have to actively seek out, either by becoming a paranormal investigator or living in a haunted house, and even if you do the latter and it becomes too much to handle, I'm sure you can just go into BB and change it to a normal residential lot.

All in all, this seems like the kind of pack that you can perfectly just buy for the CAS and furniture (or Bonehilda) without having to worry about the gameplay features getting in the way. Doesn't mean there won't be a lot of bugs at launch that will need fixing, though, so better prepare for that...