How would you respond to the following Protestant arguments against the Catholic Church?

I got into an argument with a Protestant friend concerning Catholic dogma. Below is a list of his arguments against Catholic teaching. How would you respond to the following Protestant statements to defend the Catholic faith?

1. Praying to the Saints for intercession is unneccessary. Why do you need middlemen when you can pray directly to Jesus Himself?
2. John 6 doesn't literally mean eating Jesus's flesh and blood. It only means "holy communion".
3. Those Marian apparitions are the work of Satan.
4. You don't need Mother Mary. You only need Jesus.
5. You only have to believe in Jesus Christ to be saved. It's that simple.