Now that you have read this chapter on credit cards and consumer loans, what would you recommend

Question:

Now that you have read this chapter on credit cards and consumer loans, what would you recommend to Zachary Cochrane regarding?
1. His approach to using credit cards, including the number of cards he has?
2. Estimating the credit card interest charges he is paying each month?
3. How he might lower his interest expense each month?
4. Consolidating his credit card debts into one installment loan?