I rewatched the pilot for the first time yesterday and noticed how Cooper mentioned Agent Sam Stanley and how James mentioned exactly what Laura did in the FWWM film (i.e. "You killed Mike" and shouting "I Love You, James" before running off).

Do you think that Lynch and Frost had this all planned out, all the events surrounding Laura's death, before they made the pilot or do you think that they just included these bits in FWWM for the sake of continuity and that they worked well.

Perhaps, yes.  What is probably an easier explanation, however, is that Lynch and Engels re-watched the pilot episode before/during the writing of FWWM.  And only the pilot, it seems, since there are so many continuity errors with the film and the rest of the series.

To answer your question: I think they included those bits in FWWM for continuity and it worked well. I suspect Lynch thinks of the pilot as more of a film than a TV episode. (It was released as a film in some countries, with the tacked-on ending.) To me, watching them back to back is almost like watching one continuous movie. I think he was less concerned with making FWWM adhere to every little detail of the later TV series (this isn't a director who appreciates limitations), but that doesn't bother me. Much.

(this isn't a director who appreciates limitations)

WHat I have done, and what I suggest to all who have an evening to kill....is to watch the movie FWWM, and then the pilot right afterwards.

It is often so uncanny how well the two fit together (with the exception of James good mood at school)

However, it is especially interesting to see Leland suffering so much, after you saw FWWM right before. 

Agreed, agreed, agreed -- watching FWWM followed by the Pilot is very rewarding.

>>>Or subtlety.

Not a big FWWM fan? I think it's pretty subtle. It's way more subtle than the actual series when it comes to the possession issue.

Maybe, but it's still not exactly subtle.  Perhaps "less obvious" would be a better description.