Because you burned them in the wrong format or you did not finalize the project. This must be done in iDVD and not in iPhoto.
You will need to save the pictures on a flash drive, CD, or DVD, in order to load them on an iMac.
The best way would probably be to get a hardware specialist to download the photos of the main drive of your iMac.
no
Yes, just insert the CD and follow the directions.
You would need another device to connect to it.
If your Mac has crashed and you have lost all data then unless you made a backup of all the photos they cannot be replaced. If you used Time Machine and your iMac was connected to an external hard drive then all your photos are on that external hard drive. Simply open Time Machine and restore all the photos to iPhoto.
Yes
Sure, just copy them to a CD or Flash Drive.
No it will not play a 6" disc. It will play a CD or DVD.
Open iPhoto. Insert the Photo Disk. iPhoto will see the disk and ask if you want to import all or selected photos. Open the Finder. Insert the Photo Disk. Open the Photo Disk and find the photos you want to import. Create a folder or folders on the laptop. Drag or copy/past the photos to the locations you wish. Eject the disk. The iPhoto app and the Preview app can show the photos. A free slide show app is called Phoenix Slides. See Links
Windows Movie Maker is designed for PCs, not Macs.