Will the people who are not the actual wrongdoers but adopt a passive attitude towards the widespread evils be affected by the punishment from God?

Verse 25 of Chapter 8:

And guard against that mischief which will not bring punishment in particular to the mischief-makers alone from among you, and know that Allah is severe in inflicting punishment.

However, if there exist (some) good people asking His forgiveness, God would not send down a torment on that habitation:

Verse 33 of Chapter 8:

At that time Allah would not send down any torment on them for you (prophet) dwelt in their midst: nor does Allah chastise people while they are asking His forgiveness.

How strongly does Quran emphasize saving an innocent human life?

Verses 32 of Chapter 5:

That was why We prescribed this for the children of Israel: "He who killed any person, unless it be a person guilty of manslaughter, or of spreading chaos in the land, should be looked upon as though he had slain all mankind, and he who saved one life should be regarded as though he had saved the lives of all mankind." But the majority of them went on committing excesses in the land even after Our Messengers came to them one after the other with clear directions.

Explanation: A person who willingly kills an innocent person possesses such a cruel heart as to kill other people and therefore killing an innocent human being is equivalent to killing the entire mankind. On the other hand, a person who saves a human life possesses such a beautiful and courageous mind as to save the lives of all mankind.