If your pastor is wrong about what's in the Bible, is it wrong to question him about it or openly disagree with him?
A part of the answer to this question must be how you approach the disagreement. "Flee also youthful lusts; but pursue righteousness, faith, love, peace with those who call on the Lord out of a pure heart. But avoid foolish and ignorant disputes, knowing that they generate strife. And a servant of the Lord must not quarrel but be gentle to all, able to teach, patient, in humility correcting those who are in opposition, if God perhaps will grant them repentance, so that they may know the truth, and that they may come to their senses and escape the snare of the devil, having been taken captive by him to do his will" (II Timothy 2:22-26). Are you disagreeing with him to win or to win him over to the truth?
What often happens is that your preacher won't like anyone questioning his statements. He is "in charge" and he won't like it that someone questions him. The proper attitude of a Christian is: "But even if you should suffer for righteousness' sake, you are blessed. "And do not be afraid of their threats, nor be troubled." But sanctify the Lord God in your hearts, and always be ready to give a defense to everyone who asks you a reason for the hope that is in you, with meekness and fear; having a good conscience, that when they defame you as evildoers, those who revile your good conduct in Christ may be ashamed" (I Peter 3:14-16).
The reality of the world is that there are a lot of false teachers roaming around. It is to the false teacher's advantage to keep people from looking closely or questioning what is going on. "Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world" (I John 4:1). You see this in the attitude of the early Christians. They didn't just accept whatever they were told; they verified it. "These were more fair-minded than those in Thessalonica, in that they received the word with all readiness, and searched the Scriptures daily to find out whether these things were so" (Acts 17:11).
For example, you have asked me numerous questions and I've answered with what I know and relevant passages to back up my statements so that you can check them and me out.
If your preacher doesn't want to be asked questions, answers without backing his point with the Scriptures, or clearly misuses the Scriptures (II Peter 3:15-16), then it is time to seriously consider finding a church where the members and its leaders respect God and follow His Word. You have to be responsible for your own salvation. "Therefore, my beloved, as you have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling; for it is God who works in you both to will and to do for His good pleasure" (Philippians 2:12-13). You can't tell Jesus on Judgment Day that your preacher misled you when you have God's Word in hand.
And as you ask a question, you need always to be prepared to find out that you might be wrong on a particular issue. There might be a passage that you overlooked that changes how you view a subject. You might learn that you tried to put 2 and 2 together and ended up with 5. Those times are fine, it is a part of the learning process.
But to ask, to check, to reason through God's teachings is what you should be doing. Then, one day you'll be passing your knowledge on to other people.