No. Eligibility for the earned income tax credit is based on income, not age. The amount of the credit varies with the number of qualifying children you have. A modest credit applies even if you have no such child; the credit amount (and the income limits for eligibility) scales up for one child, two, children, or three or more children.
For calendar year 2007, taxpayers covered by an HDHP may contribute up to the lesser of the annual deductible or $2,850 ($5,650 for family coverage).