We recommend running Alpha over 10-12 weeks which allows time for guests to explore, discover, and process the information.
It's best to show all the videos since each one builds on the other and together they provide a holistic experience and understanding. But if you are really pressed for time, you could show a talk or two after your Alpha is over. Here are some ideas:
Option 1: You could show the "Telling Others" video as an intro to Home Groups for Alpha guests. You can follow it up with the Life Shared small group series (if they are mostly Christians!) and continue the conversation.
Option 2: You could save the video "How does God guide us?" to Google Drive temporarily and share the link with your guests to watch on their own. This video includes content that is covered in the other videos (Bible, Spirit, Church). Remember to discuss this next time you get together.
Another option is to wait until you have a bit more time to run a full Alpha, and that way you won't feel rushed. This 3-minute video explains why it's important to run all the Alpha talks.