I know less about the age rating bands. Off the top of my head, it's to smooth costs over a lifetime. So it's a wealth transfer from your young self to your old self, if you have typical health care costs over your lifetime: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1361028/
edit: http://www.rwjf.org/content/dam/farm/reports/issue_briefs/20... for more on age banding.