When it comes to graduate education, I left to Finland where universities do not charge fees (all university education is free),
It's not free, it's paid for by the Finnish taxpayers. Yeah, it's a neat loophole, but it's pretty douchey for you to go to Finland, get your advanced degree, then go back to your home country and leave the Finnish taxpayers holding the bill for it all.
You're perfectly allowed to defend yourself/family. A gun isn't the only means of doing so.
Except in the real world, a 100 lb woman cannot beat up a 250 lb man and people cannot dodge bullets or catch knives in their teeth. You watch too many movies. The reality is that a gun is the most effective method of defending yourself, especially for people who are physically weaker.
Yes, there is a culture of violence in the USA. And yes, allowing everyone to own guns is part of this culture of violence.
Which is supported only by your emotions and not by evidence. Literally close to half of the adults in the US own guns (and we're just talking the non-criminals here) - if guns had anything to do with "a culture of violence", the US would literally be a war zone. Hell, data on those who get concealed carry permits shows that they are the least likely people to commit a violent crime and have a significantly lower rate per capita of committing violent crimes than police officers - yes, that's right, you're several times more likely to be murdered by a police officer than to be murdered by an ordinary American that carries a concealed gun.
If everyone agreed on a choice, they could elect anyone they want
No, they can't because the existing political parties control who gets access to the ballot. Sure, you could try to do a write in campaign, but there's all sorts of legal loopholes to make that incredibly difficult. The existing system will not change that in order to make it easier for you to remove them, they are currently in fact making it harder for you to have any choice between the Republicans and Democrats. That's one issue that Republicans and Democrats are very bi-partisan on - doing everything possible to block anyone else from the ballot. You have a delusion that the existing political parties will vote to end their reign simply because you tell them to. Ron Paul is a great example of this - he was too popular, so the RNC changed the rules for the primary to ensure that their preferred candidate (Romney) won. The Democrats are no better with the incident in 2012 of the members soundly rejecting putting religion as part of the party platform and then the DNC put it in anyways to try and get more religious people to vote for Democrats. Corruption is beyond rampant and you will not eliminate the corruption by playing by the rules instated by the corrupt politicians.
I'm saying that it's almost impossible for an honest person to get elected and that even the better people that get elected are rapidly corrupted by the new-found power. It's not stupid to vote against that single issue because 1) incumbents almost always get re-elected and 2) they can always BS and claim something prevented them from achieving their goals and that they "need more time" or that there were "bad things in the bill" and that they didn't want to cause more harm than good.
Variables don't; constants aren't.