Does anyone know of a way to set up project so that my un-started tasks with slack will automatically move with the current date?



Martin

Not without programming and even then, I wouldn't encourage you to do it. Built in to Project is the ability to move tasks or remaining work forward to a new status date.

1. update your tasks with the correct progress.
2. Tools > Tracking, Update Project - "Reschedule uncompleted work to start after".

You should never have remaining work in the past - whether the task is critical or not.