I got lost about the time Multipart of Singlepart came into play. So, I am really not sure of the answers to the questions.
1) I tried a bunch of tools and couldn't get snything that looked similar
2) I just used the conservation layer on top without any transparency...that blocked out the sites you couldn't use, leaving the potential sites visible
3) since I got lost and really didn't understand this, I knew if I got any results from this question, it wouldn't be accurate