Yes, They do need to do a whole lot of questioning on the bible, since there is a lot in it that is not true at all. There is not god that is ruling this earth, and we are all here by ways that have been backed up by science.
There are many things about the bible that should be questioned on who the real authors of the scriptures actually were, since there is no clear and concise way to say who wrote what I believe Paul's epistles should be questioned and investigated to see if there was perhaps somebody else who could have authored them.
I think the time for questioning the actual authorship of the Pauline Epistles passed on about two thousand years back. Biblical scholars have debated the question for centuries, and their findings have always been "we just don't know." It's likely that many of them were based on original manuscripts by Paul, later reformatted by Aramaic scholars.
No, the authorship of Paul's epistles should not be questioned, because they have already been vetted by authorities and found to be authentic. Paul had a very distinct writing style. His letters to the churches evidence enough details that he was actually there, enough that he was able to give direction to the different churches.
I believe that unless you can 100% prove something wrong, then there is no reason to discredit the source. I am a Christian and believe what is written in the Bible. Believing what is in the Bible has made me the man I am today. I wouldn't change a single word from the Bible.