You likely should consult with an attorney as to what your responses should be.
What you do not ever want to do is misrepresent a material fact (lie) in your immigration applications. Being charged by the immigration services of lying can have severe consequences to you (such as deportation, lifetime bar in re-entering the US).
Your husband appears to be an overstay. That is, he entered the US legally but overstayed his authorized stay. As an overstay, he is subject to deportation at any time. The government can discover his unlawful presence at any time (such as when he is on the ferries or at the airport or stopped for a traffic violation or when you fill out the N-400).
Once you are a US citizen, as your immediate relative, your husband's overstay likely will not be held against him if he adjusts status in the US.
Consult with an immigration attorney immediately. Based on the fact pattern, you may need to file some documents with CIS prior to you filing for your citizenship. However, more information is needed. The critical question is what type of visa your husband used to enter.
You cannot misrepresent yourself. Your obtaining citizenship may be the key to the immigration status of the entire family.
Immigration attorneys can practice throughout the country because immigration is federal law. Choose the attorney you want to represent you.