This is a very wordy thread, so I'll just say my piece and go.
Do I imagine that we would have to, in the course of any of our lifetimes, take arms against the Government of the United States? No, I do not. I don't think any of us will let our legislators take more rights. This is why we have regular elections.
Do I imagine that if we had to, the majority of military and law enforcement personnel would fight against us? No, I don't imagine that, either. All military and most LE have sworn to uphold the Constitution, second amendment included. Many are pro-gun.
Do I believe that what military and LE that would be against us would wage full war, with bombing and gunships and such? No, I don't believe that would happen. It would cause too many non-combatant casualties, and too much property damage. It would bring too many against them.
Would I go around actively attacking soldiers and police? No, I would not.
Would I defend my property and my rights if I were attacked? Yes, I most certainly would. If they open fire, I open fire. I may die, but I will not be the aggressor, nor would I ever want to be. That's it, plain and simple.