So, you're admitting that we live under an unassailable oligarchy, now, which is not at all what the founding fathers intended? Good. I agree. Democracy here is an illusion, so what's the point of voting when you're forced to choose between bad and worse? What a joke. Voting has become nothing more than humoring a feel-good farce.
Gun ownership isn't about taking over the government; it's about taking as many of the jack-booted government thugs with you as you can when they finally come for you. They're not nearly as likely to come for you as long as there's a fairly good chance that they're going to get shot.
As to your second point: Why can't we just shoot the idiots when they enter a crowded place and open fire? And if people want to kill themselves, why can't we just let them?