Special effects, rendering and what not

Our video is supposed to show the contrast between being in the 50's and being in the modern day. To do this we have made the first half of our video black and white. There is a scene where she goes up a set of stairs and we have added a flash to it so it looks like she is passing through a time portal. This flash has been added between clips on the stairs. After this we have kept the rest of our video in Technicolor to show our main character entering the modern times. I have also found that the video takes longer than the required 3 minutes so to add everything else in such as the titles and the film production logo and various different things that could be added would take the video up to five minutes roughly so we may have to cut our video and delete clips that we may not need. The clips are being rendered at the minute so we have a clearer view of what needs cutting and editing and what we can do to improve it. I can tell that it will take a while as there are 6797 frames that need rendering but hopefully I am able to leave it unattended (with a nifty DO NOT TOUCH sign) and it will render successfully before I come back at dinner time. I made sure I saved the work before hand so even if it is unsuccessful I will be able to redo the rendering process without many complications. I am also going to stay back after school so will hopefully be able to make some great progress with the editing and make sure everything looks as good as it can be.