1) depending on the HDD anywhere from 100,000 to 200,000 Hr and the SSD 100,000+ rewrites. Both drive types should last you between 5 to 10 years depending of the kind of use
2) the should not loose any info no matter how many years they are stored. I have HDD that are 15 years old and if I connect them to my computer the data is still there.
a burned CD/DVD will loose there data after a few years depending on light exposure.