Proverbs 15:22 is talking about planning for practical matters.
Proverbs 3:7 in context is talking about trusting Jehovah.
"Trust in Jehovah with all your heart,
And do not rely on your own understanding.
In all your ways take notice of him,
And he will make your paths straight.
Do not become wise in your own eyes.
Fear Jehovah and turn away from bad."
At 1 John 4:1 in context, John told anointed Christians the following:
"I write you these things about those who are trying to mislead you. And as for you, the anointing that you received from him remains in you, and you do not need anyone to be teaching you; but the anointing from him is teaching you about all things and is true and is no lie. Just as it has taught you, remain in union with him. (1 John 2:26,27)
In chapter 3 he tells how to tell the difference between a trustworthy person and someone who is not trustworthy.
Then he said at 1 John 4:1 "Beloved ones, do not believe every inspired statement, but test the inspired statements to see whether they originate with God, for many false prophets have gone out into the world."
The way to "test the inspired utterance" is not to consult with others as with practical things like in Proverbs 15:22. The way to "test the inspired utterance" is to consult with God by means of His Word and holy spirit. If the teaching of a person doesn't harmonize with what is written in the Bible and if it doesn't harmonize with God's personality as reflected in the Christ, then the "inspired utterance" is false. Just because a lot of people believe something doesn't make it true. You can consult a million people and they can all tell you something, but that doesn't make it true. (Take the "Kingdom in 1914" teaching for example - millions of JWs believe it but that doesn't make it true...)
1 Corinthians 3:18-20
"Let no one deceive himself: If anyone among you thinks he is wise in this system of things, let him become a fool, so that he may become wise. For the wisdom of this world is foolishness with God, for it is written: “He catches the wise in their own cunning.” And again: “Jehovah knows that the reasonings of the wise men are futile.”"