This assignment seemed easy enough, but I'm sure I missed something somewhere. Here are my answers to the questions.
1. I used the symmetrical difference tool. I don't know why I chose this particular tool, but I did not notice any big differences.
2. For the conservation area I used the erase tool.
3. There were 6 features in the possible sites layer. The largest was 3.680903 and the smallest was 0.377479.