1) What is the size do I need to set for Maximum size for backup-to-disk files?
Ans: Default is 4GB but since you are going to backup 150+ GB of data i would suggest 20-30GB
as the max size.
2) What is the number do I need to set for Maximum number of backup sets per backup-to-disk file?
Ans: I would stick to default i.e 100
3) How many media sets do I need to create?
Ans: 1 media set
4) For each media set I create, how long should I set for Overwrite protection period and Append period?
Ans: 2 weeks of opp for full and inc, after 2 weeks data will get ovwerwritten as per your plan.
5) As I backup to harddisk, what is the use of Retension media before backup?
Ans: not clear about the question.
6) How many jobs do I need to create to fulfil the above strategy?
Ans: 2 jobs, 1 full and 1 incr