Here are some quotes from Catholics on the subject:
As to changing the word of the Bible:
"The underlying idea behind the protestant reformation is the idea that the bible alone is the only rule of faith. The bible does not support this belief."
from:
http://www.infpage.com/concordance/additional.htm
Salvation modified:
"Martin Luther, wanting to avoid the responsibility of doing good works, promoted the idea of faith alone as a means of salvation. The Church has always taught that faith, hope, and love (charity) are required for salvation. The only time the expression "faith alone" is mentioned in the bible is in James 2:24, where the author says Abraham was NOT saved by faith alone." --from same site as above quote.
"Good Works in Sanctifying Grace are Necessary for Salvation"
http://www.scripturecatholic.com/salvation.html#tradition-I
Compare the above two quotes to John 3:16. They are not consistent, one has to be right, the other wrong.
There are hundreds of examples, so this is just a few. Go to Google and enter "reformation" and you will find many articles on the topic of Christianity v. catholicism.
The Catholic Church has more in common with Islam than Christianity. And America didn't have a Catholic President until 1960 because from 1776-1956 Americans did feel that the influence of the Catholic Church was dangerous to our founding values-- no different than they would have considered the doctrines of Islam today.
Agree with the concern or not, it is a part of American History.
Just because Catholicism does not adhere to your (obviously protestant) interpretation of the Christian faith, does not mean it is not treated by historians as the Christian Church.
Plus there are millions of Catholics who would disagree with you calling them unchristian, and with good reason.
Jesus said I am the way the truth and the light, no man comes to the father but by me and you are by definition a Christian if you believe in Jesus and believe he is what he says he is. Notice when Jesus said no one comes to the father but by me, he did no tack on a bunch of other requirements such as believing in the absolute authority (and divinely Inspired origin) of a letter written to a slave master by Paul (Philemon anyone?) Could I interpret your attempt to tack on addition requirements to go to heaven as being unchristian just like you do to the Catholics?