In regards to eating meat

[Tenet Nosce]

I prefer not to measure each person's compassion in a game of "who's the purest of us all."

Great!

The 'simple equation' isn't based on any sort of measurement of our compassion.

Either/or statements don't allow for shades of gray. Many people feel compassion for their own pets, but not for other animals. Some people feel compassion for cows, but not sardines. A few people feel compassion for both cows and sardines. Hardly anybody (that I know of) feels compassion for cockroaches.

it's based on whether we are applying whatever amount of compassion we are capable of

I believe we are capable of infinite compassion.

which entails first making the choice to actually feel compassion

As near as I can tell, feeling compassion comes quite naturally to most humans.

and then doing the best we can

I find no sooner do I attain a personal best, then a new one appears on the horizon. Thus, I am perpetually falling short of what I perceive to be best. Thus, rather than striving for an unattainable ideal of "best", I strive for "improving".

to contribute to animals suffering only to the extent necessary for individual metabolism.

Yes, I agree with this, and is why as a general rule I no longer purchase factory-farmed meat, and minimize my consumption of meat. Red meat in particular. I haven't yet found myself desiring to cut back on the sardines. But perhaps one day I will!

Either we're doing the best we can, or we aren't.

Yikes! Another one of those either/or statements. I will stick with "improving".