Re: CD Life Expectancy
Storing data is OK as long as you have the means of playing it back. Otherwise you should keep a hard copy of the original.
I have some of my gran's old 78 records (analogue data and hard copy all in one!). Fortunately I also have a playback device - the old wind up player she played them on. I managed to get some brand new needles on e-bay and have the mechanical skills needed to keep it running as long as I remain on the planet. I also have an original media lithograph (hard copy original) taken in 1865 of gran's mother as a baby, sitting on her grandmother's knee.
If you want to preserve digital data over a guaranteed lifetime, you're going to have to make multiple back-ups and restore and re-save them according to a regular schedule. There's no other way - but whatever you do, don't ditch the original copy if you have it!