Here are the texts of the references you quoted:
2 Tim 3:16-17 All scripture is inspired by God and is useful for teaching, for refutation, for correction, and for training in righteousness, so that one who belongs to God may be competent, equipped for every good work.
Where in that does it say that Scripture ALONE is enough. Sure Scripture is is important, but it does not say that Scripture ALONE is essential for correction, training in righteousness, etc.
Also, during Paul’s time, only the OT is considered Scripture.
2 Peter 3:15-16 but sanctify Christ as Lord in your hearts. Always be ready to give an explanation to anyone who asks you for a reason for your hope, but do it with gentleness and reverence, keeping your conscience clear, so that, when you are maligned, those who defame your good conduct in Christ may themselves be put to shame.
Again, nowhere here do we find Peter saying that Scripture ALONE is enough.
Matt 4:4,7,10
4 - He said in reply, “It is written: ‘One does not live by bread alone, but by every word that comes forth from the mouth of God.’”
7 - Jesus answered him, “Again it is written, ‘You shall not put the Lord, your God, to the test.’” 10 - At this, Jesus said to him, “Get away, Satan! It is written: ‘The Lord, your God, shall you worship and him alone shall you serve.’”
So for the third time, where in the above verses from Matthew does it say that Scripture ALONE is sufficient.
**Matt 15:3-6 **He said to them in reply, "And why do you break the commandment of God
3 for the sake of your tradition? For God said, ‘Honor your father and your mother,’ and ‘Whoever curses father or mother shall die.’ But you say, ‘Whoever says to father or mother, “Any support you might have had from me is dedicated to God,” need not honor his father.’ You have nullified the word of God for the sake of your tradition.
Now this particular last one is the most ridiculous support you have supplied. This highlight’s the protestants’s ugly practice of chopping up scriputure which leads to all kinds of ridiculous exegesis.
Did you even bother to read verses 1 & 2? If you did, then you would know that the tradition Jesus is talking about is a man made tradition of washing of hands before eating a meal.
So here is a little advise, before you start throwing out verses, read the entire passage first.