Questions about mourning

Greetings to the Honorable Rabbi,
My father is in mourning for the passing of his late sister.
Each of us has an independent business, but my business purchases goods from my father's business and sells them at a profit. I have access to the warehouses and suppliers he works with. In practice, my father purchases the goods and transports them to my office abroad, where I market them. In Israel, he allows me to use his office for logistical purposes, free of charge.
I would like to know:

1. Am I allowed, during my father's days of mourning, to continue my activities with his business — to promote goods, to use the business name for entertainment purposes?
2. In addition, I appointed an employee on my behalf (employed by me) to go through goods belonging to my father, an action that was done for the benefit of my father's business, even before the beginning of the mourning period. Is there any impediment to continuing this during the mourning period, or is it permissible?
3. My father has his own broker who works on my father's goods and he earns a percentage of the sales. He doesn't have a fixed salary. Can he continue to work on my father's salary? He must call my father to approve the deal.
4. If there is any doubt that he is stressed about money, we usually advance a few days. Today is the payment time and he is worried that if everything is delayed for weeks, is it permissible to pay him?

Thanks in advance for your help,