You have a lot there :) I have created an issue make it easy to discuss this further: https://github.com/ToroCraft/ToroHealth/issues/21. I have answered the questions that I could and left some questions on the the others. Thanks for your comment!
That is a good idea. I am not sure if I can tell for sure if the entity is hostile or not 100 percent of the time, but I could take a guess based on what base entities it extends. I have filed an issue for this request: https://github.com/ToroCraft/ToroHealth/issues/20
Set the Health Bar Display to OFF. I will probably not spend time documenting the options as we are working on a new ambitious mod and want to focus on that. Also, I think the options are pretty straightforward. Just play around with them and it should become clear what each option does.