1. Yes, the directory can be set to require the user to login before being shown.
2. Instead of Form, I suggest using Link instead. Your users will be able to be able to input their details and have it moderated or not by the admin. Changes would also be moderated or not. The intent with Form is to accept moderated anonymous entries from site visitors.
3. Sorry no, there is no custom field support at this time.
4. Yes, but you need to use Link.
5. Sorry, no.
6. Not sure I understand the question.
7. Yes, currently the Pro pack include every extension and every template listed on this site.
8. Technically, 30 days support forum comes with the purchase for the items purchased. I only say technically because I have not been enforcing any limits.
I hope that addresses your questions and concerns!