Hullin 111: Dairy/Meat Equipment

What if you roast a liver with other meat? Over a fire is acceptable, because the blood would be burned out, but an udder is not, because of the milk being absorbed. Except that there's a machloket, where the reverse positions are taken. Also, fish that was put in a meat bowl that doesn't have meat in it at the time -- can that same fish be eaten with kutach (the very dairy sourdough fermented food)? Will that meat give off flavor that would combine (in a prohibited way) with the kutach? Plus, the pressure from the edge of the knife as a factor, and the sharpness of a food itself, like radishes (as compared to cucumbers).