Your Sister-in-law
Yes, I suppose that they would be sister-in-laws. Because your sister is your husband's sister-in-law, and the other sister is his sibling, then I suppose they would be sister-in-laws.
Your brother would call your husbands sister by her first name. Or, "my (sibling's) sister in law.
No. Your husband's sister-in-law is either your sister or the wife of one of his siblings. If she is the wife of one of his siblings, she is not related to you.
Your husband's cousin's sister is also your husband's cousin. You are not related to your husband's cousin.
There is no common ancestor, so you aren't really related. Related by marriage is one way to describe the relationship.
sister in law
You aren't related. You do not share a common ancestor.
you call her your daughter's husband's sister
Since your sister married a woman then her mate would be your husbands sister-in-law. However, if the woman your sister met dresses and acts like a man and your sister's mate requests it then she would be your husband's brother-in-law.
You aren't related by blood, however, he would be referred to as Uncle.
The only way she is your sister-in-law is if she is directly related to the person married to you(or legally related)
Mom