It would appear that it's you who is going to war against your HOA, not the other way around.
Installing a flag pole, as noted before, comes with certain legal protections that an HOA cannot get around. They're popular with the Ham radio community for that reason, you can hide an antenna in it.
While the CC&R that you cite is a bit general I would bet there's one regarding decorations for holidays. When you chose to move to this community you gave up some control and agreed to the enforcement mechanisms in order to preserve property values, appearances, etc. I suspect that a glued on rat on top of your mail box would not be considered "first class and properly painted condition".
There are a lot of things to square off with an HOA over but is this really one of those things? A toy rat on a mail box? Perhaps an examination of your priorities is in order if this is what grinds your gears.
The HOA are not Nazi's. Nazi's killed millions of people for the sole reason that they were different than them - not just us Jews - and launched a global war of domination. Millions of people died to defeat them not counting those in the death camps and concentration camps. Your HOA just wants you to abide by the terms of the agreement to which you are a party. To use the word 'Nazi' in the manner that you did is to dilute who the Nazi's were/are and what they stood/stand for and the actions that they undertook and continue to strive for.