Sharepoint file Permission request - Customize mail content

Dear Team,

We have a requirement in SharePoint while sharing files with other users. We have created few sites in our SharePoint and these sites are shared with other users. Whenever a user who is not part of request to access a link/file, a mail is sent to owner of the Site usually where admin needs to Approve/Reject the request.

Now what we need is:

a. Customize the mail text. Display 2-3 new questions for admin to select values from before assigning permissions to users. This is to make sure, File is shared with correct person.

b. Track all these requests so that we can go back and get the data in some report format.

Please suggest what would be the best way of doing this.

Regards Deepak