Goofs

Zoey's watch is burned on the subway and goes from burnt to not burnt in other scenes throughout the movie.

Rachel pulls the lever of the emergency break and it falls off. In a next shot you can see that the lever is back.

When Theo throws the keys, they pass near a large metal pole, causing an electrical arc and damaging the keys. This is impossible as there would be no path to ground. Further, if the current or voltage was as high as it was so as to melt keys, Theo would have been severely injured or killed when attempting to insert the door handle instead of the very mild shock he received.

In the Acid Rain trap, why none of the girls even think or try to hide under the taxi when they have nowhere else to go to protect themselves.

This is not a goof. There is no possibility to hide under the taxi. The taxi is not a real car, it's a device that provides the exit from the Acid Rain room: Zoey slides through a trapdoor in the backseat into the next room. This means there is no outside space between the bottom of the taxi and the street, the body of the taxi is directly connected physically to the floor/street.

In the extended version, Claire draws what she says is a lowercase Phi, but a lowercase Phi looks the same as an uppercase Phi. The letter she draws over the keypad is a lowercase Rho.

This is not a goof. There exist two forms of a lowercase Phi: one that looks similar (but not exactly the same) as an uppercase Phi, and one that is drawn more fluently, in one stroke, which is open at the top. The letter that Claire draws on the glass over the keypad is indeed a lowercase Phi; a lowercase Rho doesn't have a curve to the left of the stem.

Acid "rain" falls during a scene, falls on the padlock for the phone booth, but the character is forced to collect the "rain" in a ketchup bottle. The lock should have been dissolved already.