Thank you for your answers.
I'm of a philosophy that in cryptography no "secure is secure enough" and no level or paranoia or far fetched attack vector is too much. So your input was highly appreciated.

I strongly disagree with your instance about "external variables"; computers are precision machines, that's why they are unsuitable for generate true randoms on their own. Much of the entropy pools are user generated, or "external variables", such as mouse movements, keys entered, pixel color swaps and so on. All of them, if we ever manage to control quantum mechanics become pretty much predictable, but taken we don't they're pretty good.
Likewise radio waves are much unpredictable out of the quantum level. Yes, if a known song if being broadcast at the frequency the radio is listening, one second of such song = one chunk of the key, but entropy here is naturally given because it's highly unlikely that the radio will have perfect reception, a "crack" and "fizzz" will make a whole difference at the end result.
Also on the "attacker", there's one thing to take to account; one thing is to be physically attacked the other remotely, there're way more kids with VPN and TOR than James Bonds around. The attack vector is very physical, the attacker will have to be in a very short range of the receiver in order to overcome bad reception entropy.

One of the most basic electronic random generator is the electronic dice, it's a capacitor that will feed a 555 timer to a shift register, the timer will oscillate accordingly to the charge at the capacitor, which is set by the amount of time a user is pressing a button, where a microsecond of charge will make a whole difference to the pulses generated. You can "cheat" this by creating a machine that presses the button a very accurate amount of time, thus controlling the capacitor charge and therefore the pulses, for sure, but if you go to use this to play Monopoly with a friend, I believe he will find pretty much strange that you bring your timer device along.