If I caught my lover with my friend I would do the worst possible thing I could do to them; ignore either exist in the future.

Save a woman who is only a Mother by accident of birth or save a true Mother who sacrificed her life for you. If you have to ask that question you do not deserve a true Mother and should not be allowed the honor of saving her life.

for instance, you're on the verge of breaking down (shallow of death) knowing not what to do, but fortunately, someone just come for your rescue demanding for your soul in exchange just through the word of your mouth, later on, the spirit of comfort has engulfed you so soon and forget all the promises that you have made hither to, badly, you're happen to be among those that put him into annihilation.....and therefore, you're happen to be the Chief Justice of the federation, so judge yourself.

Not finding these hard to decide at all...

1. Partner cheating on me with friend - they are no longer my partner nor my friend. For a true partner and true friend would never do that to me. I wish them all the happiness in the world.

2. Deciding between biological and adoptive mothers - too many extenuating circumstances surrounding this as it is not detailed enough.
a. If it's a "hospital," there would be support staff to help triage both patients at the same time and you could manage to save both.
b. If it's a rural "clinic" where there is truly only 1 doctor and no support staff for miles - then being the doctor, you are bound to the Hippocratic oath and must do all you can to save both.
c. If you TRULY cannot save both and a judgment call has to be made, triage policies dictate you help the one that has the most chance of survival. And if you cannot separate your emotions from the situation, then only you can decide what consequences you can live with afterwards.
d. Personally, I would exhaust all options to save both. If it truly came down to saving one or the other, I would rather save the woman who loved and raised me (step-mom).

3. I'm dying and someone offers to save me if they can have my soul - easy... I die. My soul is not mine to give - the woman whom I love with all my heart owns my soul. And if I am single, then I still die. My soul is not something to be traded or bartered - only freely given.