You would need another device to connect to it.
Yes
You will need to save the pictures on a flash drive, CD, or DVD, in order to load them on an iMac.
No it will not play a 6" disc. It will play a CD or DVD.
On most iMac models, the CD/DVD drive is located on the right side of the computer, towards the back. You can insert discs into the slot that is integrated into the iMac's casing. However, it's important to note that newer iMac models, starting from 2012, do not include an optical drive, as Apple has shifted towards digital media consumption. If you're using a newer iMac, you would need an external optical drive to read CDs or DVDs.
Sure, just copy them to a CD or Flash Drive.
The best way would probably be to get a hardware specialist to download the photos of the main drive of your iMac.
You cannot play a DVD in a CD-ROM drive, you need a DVD compatible drive in order to play a DVD.
Put it into the E drive (disk drive) and wait. An option screen will appear, then choose 'play CD'
None, no computers HAVE to have a CD+RW/CD-RW drive but is is helpful to have one to burn cds and play them. None, no computers HAVE to have a CD+RW/CD-RW drive but is is helpful to have one to burn cds and play them.
No. A cd-rom drive cannot play DVD's. A DVD drive can play CDs and DVD's. A cd-rom drive isn't made for DVD's. It's made only for CD's, and it can't write any. It can only read.
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.
It depends on which iMac G3 you have. With the tray loading (the tray pops out towards you) there is a small hole you have to stick a paper clip into. If you have a slot loading (you push the CD in and it ejects it by itself) there is a hole on the front right side of the drive that is supposed to force the CD out if you push a paperclip into it. Otherwise you will have to take the whole thing apart.