No. It is not only inappropriate but also may make others uncomfortable. There are boundaries in communication, and this clearly crosses those boundaries.
No. Spying is generally not ethical. In relationships, trust is fundamental. If you suspect something wrong between your wife and your friend, it's better to communicate openly rather than spying. For example, in most healthy relationships, talking it out clears misunderstandings.
There are many appropriate topics for public discussion. For example, current events like new technological advancements, environmental protection initiatives. Also, topics related to art, such as a new exhibition in town or a great movie that has just been released.
No, it's not considered normal in a typical relationship. Looking at someone's private parts in this way is inappropriate behavior. There should be respect for personal privacy in a marriage.
A healthy relationship between your friend and your wife should be based on respect and appropriate boundaries. For example, they can share common interests like a love for books or gardening. This kind of friendship can be positive for everyone involved as long as it stays within the bounds of propriety.
Well, this sounds like a very tricky situation. If by 'knocked up' you mean in trouble or facing a difficult time, perhaps your wife and friend got involved in some sort of project or plan that went awry. It could be a business idea that failed and now they are in a mess. In such a case, you need to be the mediator and find solutions rather than jumping to conclusions.