Answer from cs61c-au (Robert Webb 14343043) for Question 3
A hazard unit simply instructs the stages effected to do the same instruction twice.  This is done by not incrementing the PC or the IF/ID regester.  

The hazard will not do this over and over because the unit checks the dependancy on each stage, so eventually, the dependancy will be resolve.  Mathematically, it is sure to have been resolved in 5 cycles because all previous instructions will have been fully executed.