I put some thought into this, and while the following opinion didn't get posted as a reply (I went into left field tangent mode), I thought it'd be good thinking fodder for anyone who happens to read this blog.
The problems that the "evil gun lobby" in the states has with a registry like you propose here is that it violates the spirit of the second amendment.
The second amendment was placed in the constitution for the express purpose of allowing the people of the US to keep their government in check for the inevitable time when it grows far to big and powerful for it's own good. Some posture that this has already happened, but this is beside the point.
A register like you suggest would inevitably lead to abuse and the disarmament of the citizens that the government deems "dangerous". While it sounds like it could be an ideal thing, eventually the entire population would be deemed "dangerous", thus stripping the right to keep our government in check.
Votes are just pieces of paper. When there is no check on power, those pieces of paper can be safely ignored, and thus the US representative republic now becomes some sort of sick dictatorship. It won't happen overnight, but entropy reigns every system, including political systems.
And finally, in a somewhat tangential point, firearms are just tools. Just like your car, the set of kitchen knives you prepare food with every night, the pen you jot down quick notes with, and the air powered nail gun that roofers use to put shingles up. Every single item mentioned can be used to hurt and/or kill someone, as well as it's designed task. The firearm's designed task was to allow a person to hunt for food, and defend their own lives, both of which are noble goals. You mock this in your post, but when the balance of power is no longer in your hands in a situation (say bear attack, or your friendly neighborhood tweaker that's lost his mind with a knife), you look for a way to correct that. When your, or your significant other's, life is endangered. the firearm is the great equalizer. Ask your friendly neighborhood police officer: In the hands of a competent, trained, and practiced person, the firearm is a great tool.
All tools can be used for noble and evil purposes. Please don't assume that all guns and sidearms are evil, or only used for evil purposes.