When Penguin and Gordon are talking, the number of candles on the table changes from four to two, to four, and back to two.
At the end of the episode 2.1 when Bruce was reading the letter from his father he reads, "You have figured out that the entry code is 'Bruce'". Earlier in the episode 2.1 both Bruce and Alfred were trying entry codes systematically and they had already reached the entry codes starting with the #3. On a standard keypad the #2 is pushed for the letters A, B, and C, so they should have already pushed the numbers that represent "BRUCE" or "27823".
The switch Alfred and Bruce use to set off the explosives is a headlight switch from a car. The circuit would be turned on by pulling the knob out and turned off when Bruce pushes it in, so it wouldn't work as shown.