The answer to the first question would be "an enormous ornamental bat", it creates a comic tone because of the comparison between a bat and an umbrella and the fact that they can be compared makes it funny, as well as the irony of the phrase since obviously a bat is not ornamental nor is it enormous.
The answer to the second question would be "They convey that the accusers were judgmental", the words search and scrutiny imply that something has to be thoroughly examined or under constant supervision and that is a clear example of a person being judged with or without proof.