It's pretty bad I'm not going to rehash the usual complaints. I'm going to focus first on the one character most responsible for the problems: the "victim." This episode is based on a story written in the 70s, which means the author's view of women likely comes from the 1930s to 1950s. When the kidnapper first enters the room, why doesn't the woman scream for help? She was next to a closet full of clothes and potential weapons (coat hangers and shoes--not great, but those wedding high heals could have done some serious damage). She's smart enough to deal with rusty hinges, but dumb enough to drink water she should have known was drugged. She could have... thrown the water in his face and followed it up with smashing the glass into him. She could have used the lamp he brought into the room to keep him at bay. When she gets out of the room, she leaves the knife and fork behind--sure, they're in terrible shape, and no match for a scalpel, but better then nothing. She finds a kitchen. A pot, a pan, a knife the utility drawer with scissors and screw-drivers and what-not... Any of those could have helped. She could have taken one of the fake candles and stabbed it into his eye. She could have taken the small mirror off the wall and used it to deflect attacks. Hell, she could have knocked the guy's hand up, driving the scalpel into his own face. Instead she cowers and cringes, not because it is in character, but because the script requires it.
Now, the other down side to modernizing an old book is how dated the police work is. Remember, this was the same year that CSI had been running and NCIS was going. Police have these things called computers, and the internet was something than existed. A decent search of computer records (especially once they had a name) would have taken about three hours off the run time of the case. Also running around to the various dealerships to get pictures of the different types of vans--a few minutes on the internet would have a stack of print-outs. Sure, Columbo may not be proficient with computers, but /someone/ at the police station must have been.
One of the other plot points that really bothers me: How did the kidnapper get into the room in the first place? The door wasn't forced. Did he have a key? Did he pick the lock (Looked like the hotel was on card-key system, so that doesn't make sense)? Did he jam a piece of paper into the door to keep it from properly latching when the couple went in? What?
I have no problem with the set-up. I have no problem with this not being a murder case. I have no problem with Columbo leading a task force. The problem with the villain being nuts is that there's no real logic to his actions, which makes using logic to stop him a problem. (See the 4th and 5th basic laws of human stupidity.) Columbo does hold a gun, but his look of disgust at it after the finale is appropriate.