1. The file sizes are different RAW has a significantly larger size than JPEG has a smaller file size, also RAW has much better quality since it is letting most of the details in.
  2. RAW is the bigger file.
  3. Yes, you can change the Raw file into a Jpeg by opening the photos in Raw format in photoshop. Go to files and choose save as and select from the list, jpg, choose a compression between 90 – 100%, or it will lead to a loss of quality.
  4. If I was shooting an important event I would shoot in Raw because it captures all of the details and much better quality, so you would want that picture to come out the best it can possible be.