You are right. After the NAZIs gained power in the 30’s, these camps popped up all over the country and they predate the Jewish genocide. So it was not surprising to have photos of camps. The accuracy of a 500 lb bomb from a B17 was within a half mile. Thats why we sent up to a thousand at a time with 8000 lbs of bombs a piece. We didn’t know where in the city we were hitting, but we would certainly hit something.
In hindsight people think it was a foregone conclusion that we would win the war. That was only apparent in late ‘44 when were firmly on the continent. Right up until the end of the war we had to hit their war machine relentlessly. We could have bombed their concentration camps to no avail, but we would save more lives getting that war won faster.
Bomb loads were dependent on the amount of fuel carried and a few other factors. The further the B17's were expected to fly to the target, the smaller the bomb load. Long range missions like Berlin might mean that the planes were carrying as little as 3,000-lbs of ordnance. Incidentally the B24 & the British Lancaster had much greater payloads.