Count Olaf tries to marry Violet. Violet is a teenage girl and he's really old. And what do you do when you are married? Even through it's clearly all about the money, keep in mind that Olaf was related, albeit distantly, to the Baudelaires, which is why they were sent to live with him in the first place. Think about that for a second; he has no problem with sleeping with his own, fourteen year old... let's just say cousin, for the sake of brevity. (Ironically, it's not illegal today for third cousins to marry; according to scientific research it provides more children and has less of a chance of dormant and recessive diseases from showing up. Olaf is either the grandson of their fourth cousin... or the great-grandson of their third cousin. According to Modern Day science, this would actually be better for the reasons stated above. That being said, he might also have faked being their relative to get the money.) And in this world, it's perfectly legal for a legal guardian to marry his "daughter."
Count Olaf is very grandiose in his actions to the point where any kid in the theater would fall in love with him. This was probably the intention of the director and of Jim Carrey, adding comedy in the movie and allowing kids to be more shocked by his homicidal tendencies. However, to older audiences, this ability to attract younger kids while complimented with his later obvious psychological issues makes him appear far scarier.
Carrey as Olaf starts the film as melodramatic and over-the-top, convincing people familiar with Carrey's comedy that this will be another one of his clownish, incompetent characters. There are stories that about halfway through the movie, when Olaf violently backhands Klaus, an audible gasp of shock went through a theater.
There's a deleted scene where Olaf and his troupe play spin-the-bottle and the white-faced women get picked. In the book, they are SISTERS.
Why shouldn't the clueless adults be fooled by Count Olaf's disguises in the film? They aren't nearly as paper-thin as they are in the books, where he basically just throws a dodgy fake mustache or a turban on and is apparently good to go - in the film, he clearly had to have gone through some effort to make the disguises at least halfway-believable, so it also raises the question of how the Baudelaires can even see through them to begin with.
The VFD symbol is the eye, which appears in various locations across the film. Where an eye cant be seen, a spyglass or a circular window forms an acceptable substitute, since those symbols also represent looking at something.
While Count Olafs house is packed with eyes, and Aunt Josephines home has a wide window, Uncle Montys home has more snake designs than eye designs. This is a sign that Dr Monty, while a VFD member, is more concerned with his herpetologist job than with any VFD-related job.
This proves to be his undoing, as he mistakes Count Olaf/Stephano for being a rival snake expert rather than a villainous member of the secret society he is a part of.
However, this shows that rather than be involved in anything mysterious or shady, he is a sincerely good man who has the desire and capability to take care of children.