I attend college in Missouri you sum-bitch.

Install a TV in his head, you mean?

It's kind of ironic that guns should be more free than people. America - land of the free or land of the incarcerated? (statistics suggests the latter, and you can't have it both ways).
Or, perhaps more likely, they come prepared with guns of their own.
This is why police don't carry guns (by default) in my country. They know that if they start carrying, the criminals will start carrying, and that's a bad thing.

Again, chicken and the egg. It is great to posit what-if?s, but you need to look at what-is every so often.
And, as mentioned, it is easier to carry a handgun around. But it is easier to fit a shotgun under a counter.
Either way, it is a deterrent. It won't stop everybody, but it will stop a lot. And to take that away overnight would not end well.

I'm starting to think you own a shop in a bad neighborhood or something... :) This for me sounds more like a movie cliche. I don't think this is a good motivation why firearms are good in hands of civilians because of the rarity of this situation. Like I said I doubt it's a common situation.
If a shopkeeper wants to use a firearm as a deterrent would better keep the shotgun on the right shoulder while operating the cash register with the left. Otherwise if the weapon is under the counter, when a robber enters with a handgun would be too late for him to reach the shotgun. And here is another aspect to note: the presence of the shotgun under the counter tempts the shopkeeper to reach for it instead of handing the money to the robber and this way a robbery may become a murder case (most likely the robber will be faster).
When I was making reference to the use of a panic button to signal the intervention team I was not thinking about the police. The panic button is connected to a contracted security firm which will arrive at the scene in less than 2 minutes. A smart shopkeeper may pull the time until the intervention team appears. And if the robber is gone with the money at least he still have his life and most likely using the security camera footage the police will catch the robber in short time.
There are reasonable alternatives for every situation where a firearm may seem to be the obvious solution.

Like shooting lasers from your eyes and being able to turn into a dinosaur

Actually, friend of the family is one (small chinese guy, at that :p). He doesn't carry a shotgun around with him, but he keeps it under the counter (pointed straight out). All he has to do is flick the safety and squeeze. I am terrified to hell and back (he isn't the most mentally stable person...), but it works pretty well for him. He still gets an idiot trying to rob him every so often, but most of the neighborhood idiots know not to mess with him. He has never had to fire his weapon in anger, but it sure has deterred a lot of people over the years. If said people suddenly found out that it was illegal for him to have that weapon, I suspect he would be robbed and/or murdered within a week.
And yes, if you can afford to hire a private security firm who is less than two minutes away, go for it. But places that have those tend to not exactly be in bad neighborhoods (if there were, crime wouldn't be as much of an issue).
Also: There are still problems with your magic solution of keeping mercenaries on hand: That can EASILY turn into a hostage situation. Which is even worse.
As for criminals' rights: I am not going to get into that, but you'll understand if I value the people trying to make an honest living more than the ones who want to steal and hurt people.
You are right, there are reasonable alternatives for every situation where a firearm may seem to be the obvious solution. But sometimes, the firearm IS a very reasonable alternative. Maybe not where you live, but us filthy Americans have found a few situations where it works.

maybe, but instead you can always carry a katana... :P unfortunately this is also illegal here... :)

Does that mean cutlasses are illegal too?! :(

It is illegal to carry cutting weapons for self defense. I'm not entirely sure (because I'm not preoccupied by this) but I think it is perfectly legal to have it in your home (I know people that have in their collection such swords).

By the same sort of reasoning, you can argue that the people of North Korea are completely free.

If you give then 1 and 3 not 2 and four ;-)

He means what the 1990's are referred to as the "Punishing Decade". 1 adult male behind bars for every 100 born free. Guns have no free will, but his reference is slightly poignant considering how strict the laws here are. If gun convictions had wrongful prosecution evidence like DNA in rape cases it would cost us an unimaginable sum than the millions we already pay out for those as taxpayers.
This only has to do with how the 2nd Amendment is managed, but doesn't threaten it. The NRA make worse for themselves at a podium where a child has been shot, than any liberal banging a drum circle and smoking a peace pipe crying.
It's an immense, beautiful regional country so one can become desensitized to this or that happening right down the street. Living your life your own and minding your business builds more character and is a hell of a lot more enjoyable than crying about saving the whales and restricting guns etc.

No, your argument is that Americans are free because they can choose to follow the law or not. Unsurprisingly, that goes for every human being in the world. Even the ones in North Korea. Everyone are free to make whatever choices they want. Of course, some choices have consequences, but there it is.