Time for a quiz: Which C. J. Cherryh character am I?

In honour of C. J. Cherryh being chosen as the Science Fiction and Fantasy Writers of America (SFWA, Inc.) 32nd Damon Knight Grand Master, here’s a quick quiz.

Who is the character, and from which book?

I am drawn into a team testing prototype ships that travel at a significant percentage of the speed of light

I am stamped on the forehead by an alien as a message to tell humans to keep their hands off

I am a clone

 

I am the human representative to an alien race

 

I am the captain of my ship. I rescue a hairless alien and find he is intelligent