Answer to Question 1
Site refers to the actual location of New Orleans as a town in terms of Geographic location. Situation would refer to the town relative to situations that were around. New Orleans, located on the Mississippi River is a natural port facility in terms of trade and diversity of products. It is increased in significance of ocean going ships that can come in. As far as Baton Rouge, you have a large petrochemical industry that is adjacent to New Orleans. New Orleans is also located in the middle of tourist industry trade, where you have millions of tourists going to the city for athletic events, Mardi Gras celebrations, and to view the historical city.
Answer to Question 2
One of the hazards facing this area would be a late frost that could come and affect agriculture or an early frost. The warm humid weather makes insects and parasitic pests a particular problem. Certainly these areas are in the center of the hurricane zone. Hurricanes can also spin off tornadoes and the area has also been hit by thunderstorms. Florida has a high percentage of lightning, and hail that is produced from these storms and this can be a hazard to agriculture crops. In some cases, water is pulled from the ground faster than natural recharge is replacing it, and the water table has been falling.