Should I bank my baby's cord blood?

No. You should donate your baby's blood to help everyone, not waste your money by banking it only for yourself. Details: http://pediatricinsider.Wordpress.Com/2009/02/01/cord-blood-donate-it-don%e2%80%99t-bank-it/.
Yes. That's actually a great idea. Stem cells from cord blood can be used to treat a number of conditions in both the child and other family members, and the number of such uses is growing exponentially.
No. There is no requirement that a parent should bank a baby's cord blood. Parents may choose to bank cord blood if they want to buy the "extra insurance", in that they will have cord blood available in the unlikely event that their baby needs a bone marrow transplant or their baby needs to use his own stem cells for some other reason.
Yes. Tricky question, consult with your b ask about costs for maintenance and public free options you need to assess the chances that you will use that in the future.