Continuity mistake: The hole which Non and Superman go through is square, and smooth inside. A frame later, from a different angle, its side is covered in bulky rocks and it's rounded.
Revealing mistake: The hole that Non and Superman go through is already patched, as it's a different colour from the rest of the pavement (either from previous takes or to allow the effect).
Continuity mistake: Right after Ursa cries "Superman" and is about to throw the sewer lid at him, a man with a white jacket and a big afro runs from right to left and hides behind her. When the angle changes, he is on the very far right side of the street, many meters away, running towards Ursa, repeating all previous movements.
Revealing mistake: During the Marlboro truck scene, Zod's stunt double has very noticeably longer, darker and bulkier hair, plus a thicker beard.
Revealing mistake: After coming out of the Marlboro truck, Superman grabs Zod by his feet. When he sends him flying away, Zod's been replaced by an obvious doll.
Continuity mistake: When Zod is trying to heat up the truck's gas tank, while Superman tries to cool it the number of cars around changes dramatically, with no order whatsoever.
Continuity mistake: During the big street fight, Ursa grabs a flag pole. It is either in the shadows or lit, depending on the angle.
Continuity mistake: During the street fight, after the sewer lid scene, Zod lands on a car with his legs next to each other. A frame later they're spread apart.
Revealing mistake: In the first scene when the villains are at the console, you can see Ursa's nose disappear, then reappear when Non walks behind her, then it disappears again. (01:44:30)
Continuity mistake: When Non grabs Superman from behind, Supermans hands are down to his sides. When Ursa comes to hit Superman with the flagpole, Superman's hands are now up by his chest and under Nons grip.
Revealing mistake: There are two times in the New York battle when you can see the actors are being filmed in front of a screen: 1. when Superman kicks Non, Superman in on film and Non is hovering in front of the screen. 2. When Ursa is flying towards Non and Superman with the flagpole, she is hovering in front of the screen.
Continuity mistake: When Clark walks down to the river to help Lois get out of the water, he falls on the water and she is swimming 4 meters away. When the angle cuts she is half a meter away.
Continuity mistake: The log that Clark cuts to save Lois from drowning changes style between shots.
Continuity mistake: Non enters Perry's office and kicks a plant which makes the coat hanger next to it wiggle, but not fall. When the angle changes, about a frame later, it is on the floor, several feet away from the first position.
Continuity mistake: Superman is putting the antenna back on the Empire State. first its base is brightly lightened, despite the antenna being on top. When he is about to anchor it, a split second afterwards, the base is totally dark.
Continuity mistake: After Superman holds the antenna falling on the woman's pram, in a matter of 3 seconds the parked cars she was standing in between (a yellow cab and a black car) come much closer together.
Continuity mistake: Lois is in the diner and the waiter serves her a Coke and leaves. Angle changes, the bad guy sits next to her and the waiter appears serving the Coke again. In the next shot, the angle changes again and he disappears.
Audio problem: When the villains are trapped in the Phantom Zone glass Zod cries out something against Jor-El, but his mouth isn't in sync with what he says.
Continuity mistake: Atop the Eiffel tower the climate keeps changing from sunny to cloudy within seconds depending on the angle.
Continuity mistake: Zod throws the Sheriff's rifle away and it lands next to the wheel. When the angle changes it has moved behind the wheel.
Answer: Superman was be able to kiss Lois in such a way that the heightened emotion wiped out her memory of his identity. To answer your second question, even though Lois promised not to tell anyone, Superman decided he does not want even her to know his secret identity.
Matty Blast