I disagree somewhat.
In most states, spouses are legally liable for each other's medical bills. The collection agency for the medical bill may have been within its rights on that one.
Federally insured student loans are cancelled or forgiven when the debtor dies. Send the student loan company a certified copy of the death certificate. The student loan lender will then apply for the Federal insurance for the amount owed. If it was a private student loan, this provisio may not apply. However, it doesn't make you legally liable.
You are legally liable on the one card that you had as a joint account holder.
IA is not a community property state. It is going to be tough for collectors to get you to pay for debts on credit cards that were in his name only. However, if you did own any property (i.e., real estate) jointly be sure to promptly transfer title to your name only. If the property was owned jointly with right of survivorship, it should be a relatively simple procedure to get title formally changed. You probably need to go down to the court house with a certified copies of the death/marriage certificates (and probably some valid idenfitification), complete a simple form, and likely pay a recording fee. While title may pass automatically, it would be easier and simplier if you did this BEFORE some creditor slaps a lien on the property rather than after the fact.