I really think that people should be able to attend all interest meetings if they're deciding, and not be lableled as interested in that particular group. At my undergrad, if you even attended someone else's program, you were labeled for that particular group. However,...
when someone goes so far as to start a process for another organization, and then tries to show interest in another, I don't think that is appropriate. I know when "certain" sororities at my undergrad were suspended, the other two sororites would see an increase in people at their interest meetings and programs.
I don't think that is appropriate either because it seems as if the person just wants somebody's letters, but no specific love for any particular org.