1) the frameRate() function will your sketch frame rate, so you'll know how many frames you'll be counting in a certain time. another thing you could use is the frameCount() function that will return the number of frames you refreshed since the start of the program; so, for example, if you call frameCount() when a movie starts and you call it again when you trigger a certain event, with a simple difference you'll know how many frames were played from the start of the movie to the event.

2) with the standard video library, after you called the loop() function, inside draw() a simple img = myMovie; should work (never actually tried it: i'm on linux so i don't use the standard video library)