"ever been in a bar fight?"
Yes, I was, although not in a bar it was ar public place. I even depicted it on this forum. You were unhappy when I said neither of us would be jailed for it.
"Even if you were defending yourself, you will get arrested and most likely at least have a misdemeanor conviction for disorderly conduct."
No, you don't have to. There are these things like intent, guilt, extent and evidence which will ultimately decide whether you broke a law or not. Anectodal evidence: the fight I mentioned above.
"Citizens do *not* have the right to defend themselves in extremely crowded situations unless they have no alternative."
Citizens do not have the right to trample over the rights of others unless they are preventing an even greater harm. There are some caveats, like the one you mentioned, having no reasonable alternative. There are also others, like not creating the danger you are supposedly trying to prevent. The guard may very well have broken both, by using greater force than he had to and by possibly hurting the person more than the damage the person might have done. That's what will the authorities investigate into. I also don't say he did break a law, I'm just finding it ridiculous to say it's perfectly legal for him to taze people because of his job. He can taze people like anyone else if a greater good is at stake but his job should have nothing to do with it. He is getting paid for doing something people won't do for free even though they could - another shopper can thrust himself into the crowd to save someone but none will. Yes, being a guard sometimes means balancing between legal and illegal behaviour to protect your employer's interests, but that's what you signed up for and is nothing specifically tied to this particular field.
"The guards job is to see to it they *have* alternatives, so his rights are expanded."
He can very comfortably do that in the boundaries of his citizen rights. Unless you believe that your country is illiberal since the law doesn't give you options to protect yours and others' rights or the authorities do not respect the options the law gives you, in which case you ought to campaign for a change. Or possibly overthrow the government if the situation is really serious.
"What makes a cop special? Because he is paid by the government?"
Not because he is paid by the government, but because he is acting on behalf of the executive branch of the government, which draws its legitimacy from the democratic will of its people. He is enforcing the laws of the country. If he fails to do so properly, he will face punishment. In fact, he has to do it even if he doesn't want to. He has to do it even when outside of his working hours. He also has some of his civil liberties curtailed because of his public office. It's not like the law makes policemen standing above the law, "special".
"Trust me, just because they went through an academy (and not all do that) doesn't male them any better."
I've been inside a police academy many times, I know that policemen are *gasp* regular people. But they have certain rights and obligations tied to their relation to the government. Security guards should have none of those, as a job contract between two private parties can hardly be a sound basis for extending their rights towards infringing on other private parties' rights. And I say should as from what this thread suggests, the guards do in fact gain rights other citizens don't according to the US law.