Your cousin's wife is not related to you.
The children of your wife's first cousin are her first cousins, once removed. They are not related to you.
You would be 2nd cousins, assuming that the brother's wife's granddaughter is also the brother's granddaughter. If the granddaughter is not the granddaughter of the brother, there is no relationship.
Sisters-in-law, assuming that they are otherwise unrelated. In a small town, it's entirely possible that your wife and your brother's wife might be cousins of some degree.
Your uncle's wife's brother's son shares no ancestors with you and so is not related to you - unless the brother is married to one of your cousins.
This is if you are first cousins. They would be your first cousin once removed. Since the child of your cousin is a generation away from you they are the once removed.
Ellen Cousins
Why would anyone want to sleep with their cousins wife? Are you perverted or what?
Second cousins
Second cousins.
Second cousins.
He doesn't have a wife!
Your brother's wife's cousins are not related to you and the English language has no special term for that. The same applies to the cousins of a stepbrother's wife.