im curious to know the minimum accepted ft lbs necessary for ethical kills on game per animal weight
Ethical is something we don't discuss in this forum.
As others stated, there are too many variables to say for sure.
However, I often use 1800 fps and 1000 ft-lbs for whitetails as a quick rule of thumb. Most bullets will perform at that rate although, some are on the verge of not expanding. I beleive Berger will perform at slightly lower impact velocities and Barnes requires a little more.
Having said that, damage to vital organs is the ONLY thing that matters.