First question....If teaching is so important, why does the church ignore most of what the word teaches? (see comment above)
Define "church". Many many believers live and die according to the Words in that Book. Whether or not someone does or does not ignore truth and knowledge does not determine the nature of that truth and knowledge. To think otherwise is a logical fallacy.
Second question....Does teaching help us to know God or know about God?
So . . . which is more useful towards knowing God? What He says about Himself? Or your own opinions?
Third question....It has been said that we are emptying the church by degrees, so what teaching are we talking about here?
Teaching the Word of God. What is your question here? I don't understand. Bit it sounds like you are saying, "its not working, so give up." But to really examine this "question", well . . . "it has been said . . ." Who says? What is the veracity of their statement? When you say "we", who do you mean? Who is responsible for falling attendance on some (not all) churches? Is it "teaching that we shouldn't be doing"? Is it people who cannot endure sound doctrine? Or is it that some preacher has abandoned the teaching of God's Word, and having done that, there is no power in the assembly, and people are leaving because of that?
Your vaguely worded question doesn't really specify much here, so there's not much of an answer that can be given.
Fourth question...If the Holy Spirit is going to lead us into all truth, where does the gift of teaching fit?
This is the Holy Spirit's empowerment to those selected to teach. Are you suggesting that the Holy Spirit would somehow be contrary to the Bible? Or does He teach the Bible?
Fifth question...How can it be teaching if the hearers are not allowed to question or challenge what is being said?
Seriously??? Whether someone feels that they can or cannot "challenge" the teacher does not determine the nature of teaching.
Not to be rude . . . but does anyone still teach "critical thinking"?
Sixth question...As the Holy Spirit is not welcome in most church services, how can we be taught anything?
It's tempting to simply catalog the many logical fallacies in this post (this is "complex question"), simply answered, whether you can be taught is up to you. Are you teachable? Personally, it doesn't really sound like it.
Seventh question....Isn't experience the best teacher?
How did that work when you were two? How did you learn to stay out of the street when cars were going by? Was it through the experience of getting smashed?
Eighth question....How do you know what you believe is the truth unless it is challenged or put into practice?
So God's Word is only true if you say so?
Ninth question...Isn't most teaching in the church a homily, not teaching?
Not my church. Is it in yours? Perhaps you need a more "teaching" church. Would you receive it?
Tenth question....If the teaching was according to scripture, shouldn't we expect the same outcomes as happened in scripture?
Of course! But you have to understand what Scripture says, and what those outcomes are. Noah preached righteousness. When we preach righteousness, should we expect the same outcome as he had? No one believed, and the flood destroyed them all. Is that what you think will happen? No, of course not. Its a different time, with a different agenda. A second Pentacost? Many buy into that error, but that only demonstrates their lack of understanding of Scripture.
Love in Christ,
Mark