Your first cousin's wife is not related to you because you share no common ancestor. She is your uncle's daughter-in-law, so she is your cousin-in-law, if you want to stretch a point.
They are out of synch by a generation. They would be first cousins once removed.
If your daughter is also your wife's daughter, your daughter and your wife's first cousin are first cousins, once removed, otherwise they are not related.
The children of your wife's first cousin are her first cousins, once removed. They are not related to you.
It depends! For example, are you the uncle's child? That would make you and your wife first cousins. But you are not related to your wife's uncle if your only link to him is by marriage to her.
Your cousin's wife is not related to you, so her cousins is not related to you unless she has some family connection to you besides being the wife of your cousin.
Your father's brother's wife is your aunt, but her cousins and their children are not related to you.
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.
Your uncle's wife is your aunt and her children are presumably his children, too. They are your first cousins. If your uncle's wife has children from a previous marriage, you are not related to them because you have no ancestors in common. However, if your uncle married her while the children were very young, they may effectively be treated as your first cousins.
You are not related to the wife of your first cousin once removed, or of any other cousins. If you need to refer to her other than by name, call her "the wife of my first cousin once removed," of, more simply, "my cousin's 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.
Your Father's first cousins are also your first cousins, once removed.
You are second cousins