I probably screwed up an option or something but I have people that appear to be "Attending the Reunion" in the profile list, but did not as yet purchase a ticket. How can I change the flag on their attending the reunion so that others don't view them as attending?

The Attending Reunion icon on the profiles page reflects two different sets of data: The people who have actually registered to attend the reunion through the reunion planner, and the people who have selected in their profiles that they are intending to attend, but have not yet registered. The settings in the Reunion Planner for each "event" within the reunion include checkboxes which control the display of those attending icons on the profiles page. To change what is displayed, read the descriptions and check or uncheck the boxes as appropriate.