Er...not quite. A couple of inaccuracies in your post:nunatak said:Yes, he chose the apostles to bear fruit, and he ordained their fruit should remain. He also ordained the apostles to write scripture. True the Church grew w/o a completed NT. But you yourself point out that ended after a set period of time. The "Church" as we know it today did not write scripture, but rather the apostles. And for the Church to instruct the faithful in correct doctrine, there must be a basis for that doctrine, thus the authority of the scripture over the words of men who, even when combined believers are added from all over the world, constitute the Church.
1. The faithful were being instructed by the Apostles and their successors (appointees if you prefer) before parts of the NT were even written (eg: if you go for the generally accepted 'late date' for Revelation of c.95AD, then Peter and Paul had long since passed from the scene, perishing in the Neroan persecution of 64-66AD, leaving their portions of the flock to be instructed and shepherded by their successors such as Timothy, Titus, Linus and Anecletus, for an entire generation before John started dictating Rev 1). So Scripture was by no means the only authority in the Church in the first century, and that template had remained the model ever since.
2. Who do you think was responsible for determining the 27 books we have in our NT? Who decided for example that the Gospel of John was included and the Gospel of Peter was not? I'll give you a clue - it wasn't the Apostles because thet had been dead around 300 years by then. It was the guys they appointed and left behind to watch over Jesus' Church, and the guys they appointed etc