...as for Dudman's assignments, "A lot of it is up in the air, but we know we'll have a giant dead spider to produce."

From what I can tell Aragog's death is in the film…

We see the greenhouses, but not in a lesson (Harry on Felix finds Slughorn there, but no Sprout in the movie

Yes Aragog is on the screen for about 3 minutes, but he is dead. I think it would be quite easy for you to have your friend close his eyes during that moment. Slughorn says the same words over his body that he does in the book. Word for word (I am wondering if it is sort of sad that I know that...). That is how long Aragog is on screen.

We do get to hear Hagrid and Slughorn singing about Odo the Hero, and Harry is funny and a few lines where true to the book while under the influence of Felix Felicis.

You know, I can't remember the details of what Harry said to get the memory, but I know they most definitely deviated from canon, which had surprised me at the time because up until then, the scene was very close to canon. Actually I am starting to remember, but before getting upset please remember that I am not remembering it all, and the accuracy is questionable. But the gist of it is Slughorn drunkenly starts to tell Harry about this fish he had that he loved and was so beautiful, but died. Towards the end of the story he reveals that the fish was given to him by Lily and just disappeared the day she died. Harry uses this story to persuade him to give up the memory. Frankly I thought it was rather lame. But then, I believe that what happened in the book should have been there instead, so I wasn't listening to the story with a very open mind either.