The early versions of the unofficial patch fixed most of the broken quest and scripting issues. Since then it has been pointlessly moving items around, tinkering with stats, and fixing things that were broken while doing the previous two.
The significant problem the game has had since launch is that the latter levels are devoid of content and choices. The Chinatown hub is rather sparse for quests & characters, and everything afterward is just very linear combat missions in a game that originally offered exploration, stealth, and significant dialogue choices. Presumably the developers ran out of time and money at the end, but it's certainly not going to be fixed by a patch.