Hi, Anna! No, the Ab Hits workout cannot be done as a whole video workout - that would indeed be too much for the abs all at once in terms of safety AND effectiveness, as you'd probably be looking at 60-75 minutes of straight abs and that would do you ABS-solutely no good at all.
I think that answers question #2. 10-15 minutes per workout bout, 4-6 times per week is plenty.
Annette Q. Aquajock