The 2nd amendment reads "to KEEP and BEAR arms, SHALL NOT BE INFRINGED.
If you would look up BEAR in the dictionary, one definition reads " to hold and take along; carry; transport"
In reading your post, it seems that you have appled several different requirements.
YOU state, "Do I think that training should be required to own a firearm, NO". Well, my question to you is, what then would be REQUIRED "to keep just anyone from walking into a store and walking back out with a gun tucked in their waist band". A PURCHASE PERMIT ?? and by the way, that doesn't prevent the above from occurring, just that it could be illegal. It would seem like you'll requiring something to purchase a gun and then assuming that prevents the latter. Me thinks, faulty logic.
baldeagle8888