What Catholic apologists must understand is that they must not address Protestant theology as if it were one monolithic body, but address each theological sticking point on its own. Catholicism it seems has one general theology, while Protestants may disagree on as much if not more with each other than with Catholic theology.
The main problem though that Catholics have with swaying Protestants, is that there is a good amount of evidence in the lack of capability that a human organization has to stay righteous. This is the core problem--not theological or liturgical differences. Being subject to a fallible human in Christianity rather than God is the core. And it's quite an uphill battle since the failings of Catholic leadership in history are so well known.
You are correct. If Roman Catholics are going to address Protestant theology, they must address it in “Protestant” terms. To argue with a Southern Baptist about the authority of tradition, the early church fathers, or the apostolic succession would be a waste of time. Southern Baptists do not place much faith, if any at all, in those doctrines. If Roman Catholics are going to dispute with Southern Baptists about doctrine, Catholics must confine their arguments to the Bible, as that is the only authority that Baptists recognize. One might dispute the three issues mentioned above with an Anglican, but to argue with a Baptist about these issues is futile.