Section Two – A discussion on The Catholic Church.
I cover in this chapter some of what Protestants consider to be errors of doctrine or practice in The Catholic Church. These seem to cause major problems with Protestants which si why I will cover some of these separately to other issues or doctrine or practice.  It must be remembered that the discussion in this section, while mentioning The Catholic Church, is really generic applying to all denominations that do any of these things.
This section is purely to examine some Catholic beliefs to determine if they are doctrine (in the Bible) or are just personal beliefs and practices affecting only the Catholic denomination.
I personally believe many Catholics to be Christians. They love Jesus above all else, put Him and His Will first in all things and are willing to die for Him. While They may have erroneous belief or doctrine this is not deliberate but is because they have not been shown the truths they need to fight the errors in their belief system.

The source of Catholic Doctrine
Catholic doctrine has three sources..

The Bible
Apostolic tradition
When the Pope speaks ‘ex officio’.

The Bible
There is no argument with doctrine based on a correct interpretation of The Bible as that is the only source of correct doctrine.
Apostolic Tradition
Anything determined in this category is not found in the Bible (or the would not need to rely on apostolic tradition or practice) so it cannot be used for determining doctrine but can only be used for determining practices the Catholic denomination can use. This is, of course, providing these do not fail any parts of the second test.
Ex Officio
Nowhere in the Bible has any one person been delegated the right to determine doctrine. The only delegation that his been given to The Church is for the purposes of fighting Satan and all the Pope declares ex-officio must be examined in the light of this sole delegation
So, while we can bind and loose on earth and in heaven, it can only be done in the context of fighting Satan and destroying his works and plans.
Any pronouncements made ex officio cannot be for the purposes of modifying or making doctrine but only in respect of the practices and administration of the Catholic denomination as no one has been given the right to make doctrine except The Holy Spirit and even then that was finished with The Bible (Job 32:8)
The Catholic Catechism.
This Catechism is the doctrinal statement of the Catholic Church, There are many things in it Protestants could benefit from a study of, But there are also errors that do not stand the two tests.
There is much in it that Catholic and Protestant can agree on, The doctrinal differences are not a subject for ecumenicism as ecumenical differences can only be in regard to things not in The Bible. These things not in The Bible will need to be examined in regard to the second test and if they pass all these tests they are then practices of the Catholic Church and all others who do any of them and which cannot offend anyone as they do not offend the Bible otherwise they would have been rejected because of failing any parts of the second test.
This means Protestants can ignore any catholic practices that pass the second test as God is not offended by them and that Catholics should not force those outside their denomination to practice these things as they are solely a non-Biblical practice of The Catholic church that is not important for the purposes of Salvation and of Christian living.
Remember, Satan uses things that are of no eternal significance (like the things that pass the parts of the second test) to cause  problems and disputations that are of eternal consequence because of the lack of love that is shown when there should not even be a discussion over them.