@BrotherDan
I hate semantics but maybe "throw out" is not the correct term here. Just because something is seen as "uninspired" and not "scripture" doesn't necessarily mean that it doesn't have value. We can look it as his letters as they were written and read at the time and not as they came to be regarded over the centuries. We need to keep in mind that Paul wrote his letters, not necessarily to believers nearly 2,000 years later, but to real groups of people in his day, often in answer to specific problems that arose or questions they asked. It's like listening to one side of a telephone conversation.
Jesus is quoted as saying "a servant is not greater than his master". Few who identify as Christians would argue that Paul is greater than Jesus, yet they often show this when they start with the letters of Paul and use them to interpret Jesus. To me it would seem to be the other way around. If we accept that Jesus is truth and true prophecy reflects the spirit of Christ, then we can in turn examine what others are preaching and reflecting. This includes the letters of Paul of Tarsus, this includes the letters of Clement of Rome, this includes what people write/say today.
To what the original poster brought up, Paul didn't have the benefit of hearing Jesus during his ministry and he had limited access to those who did. It comes as no surprise then that he doesn't offer up a lot by way of direct quotes. He did have the Spirit of Christ which is a teacher and taught Paul over time.