Should i take this precaution even if i use a write blocker?
You need to worry about working on an image of the hard drive instead of the original drive because even if a write-blocker has a read-access only to your hard drive(s), you must remember that a common cause of HDD failure is a head crash where a read–write head of a hard disk drive comes in contact with its rotating platter. Because this is a type of physical failure, a write blocker makes no difference.
