"shouldn’t a threatened species be completely protected unless absolutely necessary"

This is not always true in nature. To most, including myself until I worked with the Michigan DNR, it would seem that predidation would hurt a population. However in nature this is not always true. You can look at studies all over the US and Canada and see where hunting and fish are allowed that the wildlife acually thrives there. You can see this in many states with ducks, geese, and deer. In rivers once you get a line going if you don't fish it and harvest the water becomes overpopulated. This does two things 1# reduces the nutrition for the fish to feed 2# it can acually raise the water temps. enough to kill off the species. There are a lot of fly fish books that are published about this but one of the best resources is Trouts Unlimited.

If you would like to look at the rest of the issues that you raised I would be happy to but in the correct forum.

Junky