On the ageism question, 18 is the general age where we welcome people into American society as adults -- not just voting but also army service and criminal liability. I'm not opposed to moving the voting age earlier but it should be in conjunction with those other responsibilities.
You're kind of begging the question on the other two -- you've assumed your hypotheses, making it hard to disentangle. For example, you're assuming Americans haven't confronted the fact that war kills lots of people -- I don't know that's clearly the case. You're right on the cliff of using the word "sheeple."
One thing I will question -- are populist governments (which you seem to desire) really a solution to the issues of authoritarianism and repression? A movement that seems to have contempt for as many people as the populist movement does seems like it could easily degenerate into its own tyranny and purging.
The alignment of the two ages is actually pretty recent, at least in the US. Traditionally, military conscription age was 18, while voting was 21. It was moved (in 1971) due to agitation from people who argued that it was unethical to conscript people to die for their country, but not trust the same people to vote for their leaders. But that's merely an argument for why voting age should be <= conscription age, not necessarily an argument that it should be ==.
I think it a pretty good argument that the voting age should be less than the conscription age by enough that the person conscription has had a chance to participate in the voting that led to the government which is conscripting them. It sets the order of events more in line with a hypothetical ideal social contract to which one agrees by one's actions and then owes such a high price to.
You're kind of begging the question on the other two -- you've assumed your hypotheses, making it hard to disentangle. For example, you're assuming Americans haven't confronted the fact that war kills lots of people -- I don't know that's clearly the case. You're right on the cliff of using the word "sheeple."
One thing I will question -- are populist governments (which you seem to desire) really a solution to the issues of authoritarianism and repression? A movement that seems to have contempt for as many people as the populist movement does seems like it could easily degenerate into its own tyranny and purging.