Claire Forlani was cast as Trillian St. James. She even started shooting, but walked out after just three days, due to creative differences with director Stephen Sommers. The part subsequently went to Famke Janssen.
Famke Janssen's character Trillian is named after the Hitch-Hiker's Guide to the Galaxy character of the same name. Although here Trillian is her actual name, in Hitch-Hiker's it's short for Tricia McMillan.
The "Chinese M1 L1 triple-pulse assault rifles" used by the pirates are actually heavily modified Calico M-960 submachine guns fitted with 100-round magazines (as opposed to the "thousand-round capacity" mentioned by Hanover). Five non-functional rotating barrels were built around the actual barrel of each Calico and driven by a small electric motor connected to the trigger, so that whenever the gun was fired, it appeared to be firing out of the rotating barrels.
One of the few films that has no heroes or heroines. Finnegan and his crew are hired for villainous reasons. Trillian is a thief. The mercenaries are simply mercenaries.