Following that, it's objective.
you sure?
pretty sure humanism allows for abortion, including convenience abortion, which is over 90% or over 600k abortions/year . what about the well-being of the human lives that are being ended?
you haven't shown an objective moral definition of well-being itself. you've given your opinion which is presumably the secular humanist view - what standard makes that definition correct and another definition of well-being wrong?
if the foundational concepts are opinion, the resulting work is not an objective morality - it's a system built on opinion that can't be demonstrated to be more valid or correct than any other opinion