Subjacency intuitions

I've been reading an old Chomsky book, Language and Mind, lately. As usual, the moment he starts discussing what would eventually be called subjacency I find my intuitions are systematically different from his, and I'm curious: how common is this? By way of testing, here's a few sentences in English: which ones would you consider ungrammatical/unacceptable as phrased?

1. That's the boy who they intercepted John's message to.
   
2. That's the boy who he believed the claim that John tricked.
   
3. That was a lecture that for him to understand was difficult.
   
4. Which book did John wonder why Bill had read?
   
5. Which book did John think that Bill had read?
   
6. What would you approve of John's drinking?
   
7. What would you approve of John's excessive drinking of?

Chomsky's grammaticality judgements will be provided later - they're on pp. 50-54 of the book.