I will leave it simply by quoting your verse, but highlighting a word you misssed ...
Unbelief is held in parallel with disobedience. There is no cause effect relationship. There is a parallel construction here. The Bible still says that man goes to hell for sin. Unbelief is simply one of those sins.But now let's go back to Hebrews...
Who were they who heard and rebelled? Were they not all those Moses led out of Egypt? And with whom was he angry for forty years? Was it not with those who sinned, whose bodies fell in the desert? And to whom did God swear that they would never enter his rest, if not to those who disobeyed? So we see that they were not able to enter, because of their unbelief.
Hebrews 3:16-19
I think Moses would beg to differ with you on this.The sins made God angry, but that is not why they could not enter the Promised land!
You folks who are paying attention to the sins are concentrating on only the symptoms which indicate the disease which kills. [/qutoe]Not at all. The Bible never calls sin a sympton. Sin is the problem. Unbelief is a sin. There is a relationship dealing with belief/unbelief. But Scripture does not divide it as you do. When you see people in hell in Scripture, it is always connected with their deeds.
And this is what I said above about solidarity with Christ, or being "in Christ." The adulterer goes to hell becuase of their adultery (Gal 5:19-21; 1 Cor 6:8-10; Rev 21:8, etc).Think about it: if Jesus pardoned the prostitute for her sins because of her faith (belief), but adulterers are consigned to hell, what is it that made the difference? Belief. Belief in Christ. It was not the sin, but the heart, that made the difference. The sin was the same for her as for those who are hell-bound.
You will always have the problem of the text. You have put a lot of thought into getting around those verses. I find it inadequate to deal with the text itself however.