Can we have a custom role for creating retainage invoice?

Summary:

Can we have a custom role for creating retainage invoice? Basically we want the end user to create retainage invoice and want to give specific role only to create retainage invoice. Also, how do we know that there is a retainage amount pending to be paid. Do we get notification/reminder that retainage amount needs to be paid off mentioning it is closer to due date.

Content (required):

Can we have a custom role for creating retainage invoice? Basically we want the end user to create retainage invoice and want to give specific role only to create retainage invoice. Also, how do we know that there is a retainage amount pending to be paid. Do we get notification/reminder that retainage amount needs to be paid off mentioning it is closer to due date.