Nice to see that people can spit back their indoctrinations so well . . .
To try and answer and not with any intent to change your mind, since they are pre-made. Here are the arguments
1. Gun is a tool. Yes. A handgun has only one purpose, to kill people. Giving a nut case a more effective tool is NOT a good thing.
2. You can kill people without a gun. Yes this is true. But you can't kill them as fast and effectively without a gun. The Colorado case is an excellent demonstration. Ever use a sword? I have. Had he been armed with a knife or a sword, the number of dead and wounded would be far less. He also would have been overwhelmed very quickly by sheer numbers.
4. Our founding fathers ordained this and saw it as good. hmmm. I pretty sure our founding fathers didn't have 12 people in a movie theater shot to death in mind when framing the constitution. Or a 4 year old killed on a playground or . . . Guns are not necessary for freedom. Would the gun in the hand of the 4 year old save him? in the hand of his mother? Reasonable laws that are enforced are necessary for reasonable freedoms. If you don't think so, please visit Libya or Syria. Read the constitution, even the little words. None of the above scenarios are protected.
5. England and Germany are not free? Man, I can't even answer that one. Do yourself a favor and go there and ask. They aren't free to wield handguns but that isn't what they want anyway. "Freedom" as a concept is ALWAYS a trade off and not an absolute.
Again, read the part about its not ALL ON or ALL OFF. Its about reasonable protections. When we have stuff happen like this with remarkable regularity, that's a pretty good indication that reasonable protection has failed. I own guns, I taught my son gun safety. The problem here is that people look through the wrong end of a telescope and say, "I trust me to have guns and all the cool magazines, and automatic weapons". In most cases you are right.
What you really should be asking is, "Do I trust my knot headed neighbor who can't seem to park his car straight, who lurches down the street in a series of massive corrections, manages to set his lawnmower on fire every weekend, whose VCR blinks 12:00, and figures his trash looks good on my lawn, and hasn't learned how to bathe regularly yet, with a high powered automatic weapon." If your answer to this is an unqualifed yes, well . . .
The crux is determining a responsible adult. I'm saying we are failing at that right now and a realistic look would save lives.