One ticket can complete all projects, is there a time limit? That means after finishing it again I can play the same project once more?

There is no time limit; however, please requeue.
Student ID has gone missing; you can check online and buy a student ticket if possible.
There is no time limit, it can be done though the line needs to be re-formed.
Student ID has gone missing, can check on Academic Credit Network to see if you can buy a student ticket or not.