Answer from cs61c-el (David Tung 16479725) for Question 2
FSM are used in any situation where the situation is defined by the currently stored values and the input.  One could be the idea of electronic locks, like the card-keys in Soda.  Access is determined both on the state (which day it is, what time of day) and on the input (whether the person using the cardkey has access).  A second example could be the idea of automatic doors for supermarkets.  Obviously, it depends on the state of whether the supermarket is open, but also on the input of someone entering the path of the motion sensor.  A third example is taking showers in places in the middle of nowhere.  You can only get hot water if the state is that the water heater is on, and if your input has the faucet open.