About point 2. No one can say for sure. You will have to make a choice xD. I have chosen to serve him, no matter what consequences that may unleash...
Just in case you havent reached that part of the story... beware spoilers:
You said "I'm seriously scared of serving him and ending up hurt someone I care about" Later on, you meet Groth, the orc with a tusk broken, and... Nameless will give you the choice to involve him in lewd stuff... I think (I am just guessing since the text will appear in red color... xD) however Nameless is giving you a choice there as well. I decided not involve him and enjoy Nameless company myself...
We´ll have to wait to see more of his story, but I want to trust him yes or yes even if its sounds like a horrible idea. I like dominant monsters lol