If you're advocating listening to modern prophets, then I warn you, they are a dime a dozen - meaning all self-proclaimed prophets and self-proclaimed apostles are false. But the reason why people want to believe in prophets who "have a word from God" for them is because they are lazy and impatient, and want a shortcut to God's will for them without the blood, sweat, and tears of learning the Bible and what God says is His will there.
You quote some verses (which I agree with) and make some statements (which I agree with, since God does speak to individuals), but what is really your point? Are you saying that God speaks new things to people, or are you saying God speaks His word out of the Bible to the spirit of individuals? I agree with the latter and disagree with the former. Certainly people are illuminated by God's word, as in Heb. 4:12. People can obtain wisdom from knowledge of scripture, aiding them in making right choices. But in regard to doctrine and theology, the canon is closed, and there is "nothing new under the sun" in that regard.
In regard to your objection to MacArthur's statement, it's a matter of semantics and point of view. You admitted that the Spirit will not say anything that contradicts scripture. So then, in a sense, aren't you essentially in agreement with MacArthur?