Ok, I see what you are saying, but are they so essential that it would hurt to lift the limit to 20-22?
You mention all these stuff but every night I hear about something being killed or injured in a car accident.
So lets take alcohol as an example, that has no purpose, much less than a gun and it would casue much more deaths than legaly owned firearms but people don't have to own a licence to buy some. They don't have to keep their alcohol under lock and key. Hows that fair?
This is another thing were nothing will be done becasue it will affect way to many people and the party that suggests reform will loose votes.
I agree with you there. Political parties and governments are much too focused on securing votes and protecting their interests (e.g. donations made by industry businesses to persuade them to pass or not pass certain legislation). It's not a matter of nothing getting done as much as it is how little will be done.
Again, I agree with you on alcohol. On its own its purpose is to pleasure the consumer, intoxication being the consequence of this. At a glance, it's easy to say that it's a very passive past-time that affects only the consumer. If you compare it to a gun, alcohol is safer hands down, no question. Totally different purposes and no way comparable. BUT, it's not that simple. Alcohol affects the imbibers judgement and inhibition. If it screws up the person, it's very likely going to muck with whatever they do (driving, firing a gun, rape, etc).
I don't think enough is being done with alcohol, honestly. From an economist point of view, if you raise the age limit, it will have minimal impact, or very possibly make things worse. From a cultural point of view, we have social institutions such as bars and clubs, that focus on alcohol. What kind of message does that send to youngsters as they grow up and see the world? It's in our households, our venues, on advertising, and I know at highschool for us drinking was a sign of social capital. The more you drank the more badass you were seen as, which led to more credibility.
So what do you do? (ANOTHER topic

) Limit the alcohol % in a beer? Ban it? Make people acquire an alcohol license If you've kids around, putting it out of reach or in a locked cabinet might be a good idea.
Just to reiterate earlier, I said I understand why laws require you to keep ammo locked separately, not that I agree with it. If this measure helps keep fatalities by firearm down, wouldn't you want to keep it if it meant one less kid was accidentally shot at home? But how do you measure that? How do we know that this measure actually works? I mean, it makes sense and is a possible pain in the ass for gun owners, and I'm sure most gun owners would put up with the inconvenience if it meant saving more lives, but that rests on the assumption that keeping ammo in a separate safe will help keep fatalities down, something that has yet to be quantified.