I would think that the first priority with ETs would be to a establish
"friendly" relationship to ensure that the human race is not considered be
expendable, enslavable, etc. This would mean sending sending the best
diplomat available. A diplomat would be able to quickly and fully
understand the motivation for the contact and the political situation the
human race is about to step into. The potential to adapt politically to
the situation would require a certain amount of moral and ethical
"flexibility" that is the forte of diplomats not scientists.
$0,02 CDN