Is there any downside to adding our children to our certificate of deposit, savings accounts or checking accounts. The accounts are held jointly by myself and my husband. If we should die together, can our children withdraw the money at their descretion without death taxes or any other charges or taxes?

First its not a good idea to piggyback your question on someone else's. This can lead to confusion. You should start a new thread. So I've moved your question to its own thread.

If the accounts are held as joint tentnats with rights of survivorship, then the funds pass directly to the joint tenants ouside the estate.

There might be some issue of gift tax if you do this and there is also the issue of sibling rivalry if the accounts aren't distributed evenly.

Other issues, if the children would go into bankruptcy, if they would get a judgement against them, if they would just be dishonest they could just take all the money