Re security. Some valid points there in the long term.
But let's take South America for example. Kidnappings do happen on a regular basis for quick cash.
Security guards families are taken hostage in order to the get the keys to the rich houses in gated communities... then money is stolen. This is a frequent occurence. The type of organised crime you are talking about will do better making profits elsewhere. Someone can hold a gun to your daughter's head and make you go to the bank and get cash out... they don't need to ask for your bitcoin keys!
and
professional-James-Bond-ninja-operative breed of criminals
..... well, that's where your perspective becomes a bit laughable... You watch too many movies clearly
There's a few different topics addressed in this post but I wanted to comment on the security issue. Anyone who thinks that having instant access to a huge some of money that is easily transferable and pretty much untraceable wouldn't make you a target for violent criminals is being pretty naive. In 'first world' countries such as USA or UK people will commit violent armed robberies in broad daylight in banks for possible rewards of tens of thousands of dollars. They would definitely prefer to rob less well protected individuals for greater sums. It's not only South America where things like this occur.
I mentioned this in the 'how many bitcoins have you got' thread and suggested a time delay wallet similar to the safes in banks. On reflection this might just result in you being held by the violent criminals for even longer, making the whole experience of losing all your money even more unpleasant.
There is one possible solution. You ask a trusted third party such as a lawyer to generate a secret key unknown to you. You generate your own secret key. A bitcoin address is formed that needs both keys to be known to open it (this is easily done) and you transfer your bitcoins to this address. The lawyer cannot access these bitcoins.
Then in order to access your bitcoins you have to go to your lawyers office and sign a release form and you are given the other key.
But please ensure that all of the violent criminals are aware that you have done this.
Alternatively spend all of your bitcoins and your fiat as soon as you get it. I use this method and it works fine.