A bunch of question and maybe some confirms

A bunch of question and maybe some confirms

We are in the testing phase by now (bought one month the enterprise edition) 

1. There are no customer fields by now any time frame? 
2. Can we put more than one resource to a task.
3. I'm a little confused when to use Parent Task and when Task List (is there a difference ?) 
4. On the email alerts is there more information how to send mail for overdone task to the manager (escalation) 

Kind regards
Rainer Mokros