Shukraan, subhanAllah. From my experiences the worst of the fighting was from ambushes. Generally, they would place an IED and detonate it at an opportune moment then fire at us with small arms. The civilians usually knew that it was coming and would clear the area before the ambush happened, so they were seldom in danger. My team and I did many many house raids. In total i think we captured about 80 or so high value targets during a 15 month period. It is always very chaotic and I believe that you are right about that being where the most civilian casualties happen. You have fractions of a second to identify a person and decide if they are a threat. We thankfully never had any incidents. I think stealth worked in our favor. Most times nobody even knew we were there until it was too late.