There is a menu bar button (configurable) that will allow for the DVD drive to be opened. Alternatively there are the function keys. If something is stuck in it, holding the mouse on boot will also force out anything inside.
I am able to run CS4 on my G5 without issues. CS5, however, does not support PPC.
Unless that TV is 1080p, it would most likely be crap for doing anything with photo, video or heavy multitasking due to the low pixel density. It's probably 1366 x 768 isn't it?