Multiple date difference and date count in a string

Hi, can anyone help me with implementing this?

In my Dashboard I have 4 columns:

A) Number of the issue

B) Person Handling the issue

C) Creation Date of the issue

D) Comments on the issue

Can you help me with one or multiple DAX to:

1. Count the total number of the Comments placed for each issue, counting only the ones placed by the Handling Person.

2. Calculate how much time has passed between Creation Date of the issue and the date of the first comment placed by the Handling Person. Basically it can also be date of handling person's comment minus date of creator's comment + it needs to exclude weekend days.

3. When we have a longer conversation between the Creator and Handling Person, calculate how much time has passed between each comment of the Handling Person.

Here is how each cell looks like

Comments :Comments Column(text in a row)

Creation Date: Creation Date Column

Appreciate your help.