Michael Crichton wrote the part of Connor with Sir Sean Connery in mind. Indeed, the very name "John Connor" is an Anglicization of "Sean Connery".
Michael Crichton and Michael Backes quit the project, largely over disagreements with writer and director Philip Kaufman, that one of the lead characters should be changed to a black man.
The murderer's identity was changed from the book for reasons not explained by Philip Kaufman.
The Sempai and Kohai relationship is touched upon during the movie, however there were a couple of problems. In Japan, "Sempai" is often used as an address and as a show of respect to one's superior. "Kohai", on the other hand, can be considered offensive when used to address an individual directly, as it is "putting someone in his place." Hence Captain John Connor (Sir Sean Connery) effectively insults Lieutenant Webster Smith (Wesley Snipes) throughout the movie. Given that Connor is supposed to be well versed in Japanese customs, this action should be taken very seriously. "Kohai" is normally used as a reference, not an address. For example: Smith is the Kohai of Connor.
Actress Shelley Michelle, who played the girl covered in sushi, said in an interview that scene took a few days to shoot, so she had to lay on the floor for hours totally nude. The first day she noticed the crew kept sneaking peaks at her body. But after that it stopped because she figured they got used to seeing her naked. Then they hired real SWAT guys to raid the place. At first, they would keep looking at her too, but she said she wasn't shy so it didn't bother her. But they used real glass for when they bust through the windows and it was flying everywhere. She was nervous she would get cut but thankfully never did.