If I have DACA and my husband (US citizen) applies so I can get the US residency, will it be easier since I have DACA or will it be the same?

It really depends on whether you are even eligible for permanent residency on the basis of marriage to a US citizen. The fact that you got DACA does not mean that you are eligible to adjust your status since the requirements for the two processes are very different and largely unrelated. If you entered the US lawfully and overstayed, you are eligible to adjust status within the US, regardless of whether you have DACA. If you entered the US unlawfully, even if you have DACA, under the current immigration laws, you are not eligible to adjust your status to permanent residence within the US.

It will still be the same process and requirements. Since you are not in lawful status, I recommend that you seek advice from a competent immigration lawyer to make sure you meet the eligibility requirements for adjustment of status within the United States. If you came in without inspection, you may have to apply for provisional waiver if you do not have 245i benefit.

It depends on how you last entered the US. If you initially entered legally and then overstayed, you can adjust status in the US. If you entered illegally, then you would have to leave the US and consular process. However, you may trigger a 3 or 10 year bar when you depart the US. There is a provisional waiver you can apply for before leaving based on hardship to your US citizen spouse.

Your DACA approval does not make a difference. You can become a permanent resident through a US citizen spouse without having to leave the country if you last entered the U.S. lawfully.

if you entered the US illegally you may have to leave the US to get your immigrant visa in your home country. If that is the case, DACA does not help. You may file waiver if needed while you are in the US. Consult with an immigration lawyer for advise.