I'm going to focus on this statement for the moment.
What specific arguments do you wish to use to try and argue that the Bible says there should be a closed canon?
Most of the more common arguments used by critics of the church to this effect have fallen flat.
I Corinthians 4:6:
so that you may learn from us the meaning of the saying, “Do not go beyond what is written.”
II John 1:9:
9 Anyone who runs ahead and does not continue in the teaching of Christ does not have God; whoever continues in the teaching has both the Father and the Son.
Revelation 22:18-19:
18 I warn everyone who hears the words of the prophecy of this scroll: If anyone adds anything to them, God will add to that person the plagues described in this scroll. 19 And if anyone takes words away from this scroll of prophecy, God will take away from that person any share in the tree of life and in the Holy City, which are described in this scroll.
Galations 1:6-9:
6 I am astonished that you are so quickly deserting the one who called you to live in the grace of Christ and are turning to a different gospel— 7 which is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ. 8 But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let them be under God’s curse! 9 As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let them be under God’s curse!
We also have Paul’s epistles to the churches warning of false Gospels being circulated, as an example:
II Thessalonians 2:1-2:
Concerning the coming of our Lord Jesus Christ and our being gathered to him, we ask you, brothers and sisters, 2 not to become easily unsettled or alarmed by the teaching allegedly from us—whether by a prophecy or by word of mouth or by letter—asserting that the day of the Lord has already come.
We see the damage additional teaches present here:
Mark 7:6-13:
He replied, “Isaiah was right when he prophesied about you hypocrites; as it is written:
“‘These people honor me with their lips,
but their hearts are far from me.
7 They worship me in vain;
their teachings are merely human rules.’
8 You have let go of the commands of God and are holding on to human traditions.”
9 And he continued, “You have a fine way of setting aside the commands of God in order to observe your own traditions! 10 For Moses said, ‘Honor your father and mother,’ and, ‘Anyone who curses their father or mother is to be put to death.’ 11 But you say that if anyone declares that what might have been used to help their father or mother is Corban (that is, devoted to God)— 12 then you no longer let them do anything for their father or mother. 13 Thus you nullify the word of God by your tradition that you have handed down. And you do many things like that
.”
Luke 11:45-52
One of the experts in the law answered him, “Teacher, when you say these things, you insult us also.”46 Jesus replied, “And you experts in the law, woe to you, because you load people down with burdens they can hardly carry, and you yourselves will not lift one finger to help them.47 “Woe to you, because you build tombs for the prophets, and it was your ancestors who killed them. 48 So you testify that you approve of what your ancestors did; they killed the prophets, and you build their tombs. 49 Because of this, God in his wisdom said, ‘I will send them prophets and apostles, some of whom they will kill and others they will persecute.’ 50 Therefore this generation will be held responsible for the blood of all the prophets that has been shed since the beginning of the world, 51 from the blood of Abel to the blood of Zechariah, who was killed between the altar and the sanctuary. Yes, I tell you, this generation will be held responsible for it all.52 “Woe to you experts in the law, because you have taken away the key to knowledge. You yourselves have not entered, and
you have hindered those who were entering.”