Is it possible to have a TaskID associated with multiple schedules?

Additonal questions from my initial question:

 

1. Is it possible to have a TaskID associated with
   multiple schedules? 
   1. If so, if you submit the TaskID in one schedule
      will it close it in the other schedules?
2. Is there a max on the number of rows of tasks allowed
   in a schedule?
3. Once all predecessor tasks of a task are
   submitted, is it possible to have the system automatically close that task?
4. Our organization would like to create a master
   file of high priority tasks.  Is it
   possible to have the master file auto created from the other schedules?  We would like all high priority of the