The current daily mint rate is not 0.03%, but 0.017% (25 * 6 * 24 / 21e6). And it halves every four years.
Why are you dividing to 21 million, the eventual numbers of coins ? There are 11 million
now, so if bitcoins replace us dollars
now, the daily expansion is around 0.03%
Ok, let's drop the immediate obsolescence of the dollar as implausible, and say it would take Bitcoin 15 years to replace the US dollar. The block reward would halve 3 times to 3.125 BTC and the total mined by then would be around 20 million, bringing daily expansion to 0.0023%. Even in this scenario mining of bitcoins would suck a full 5 to 15% percent of the national electricity production, depending on the capital ratio.
I don't want to split hairs, but if the sheer order of magnitude of these numbers don't concern you, then you might suffer from the modern day version of the gold fever. There's just about no chance in hell a democratic society will allow such a behemoth to live (only to be subjected to the feudal whims of the early adopters that happened to be in the right forum 20 years ago, I might add).
The concept of cryptocurrency and it's privacy and liberty implications are revolutionary. The specific way bitcoins are produced in this chain is bad and can't possibly survive in the long run. Bitcoins will be replaced by better designed cryptocurrencies, there's no doubt about that.
Your core assumptions and math are deeply flawed, especially in light of ASICs, which pull ~600 Watts and churn out more blocks than their predecessors, GPUs.
Inconsequential. The difficulty will adjust to cover any absolute advantage of ASICS and as long as the mining market is worth 1 billion dollars, the money will go to either electricity, mining equipment or profits. Since the market is competitive the profit margins are thin and most resources are simply wasted.
cost efficiency will drive mining devices to be built into heaters, hot water systems etc...
A nuclear reactor dumps two thirds of thermal energy as waste heat, hot water. Because of thermodynamics you can't make electricity with high efficiency from heat alone, you need very high temperatures differentials. If there is a town near by that can use the waste heat, fine (cogeneration) if not all of it is dumped in the atmosphere or a river. Since ASICS can't exceed 60-70 degrees Celsius, there's little that can be done with that heat. Electricity is expensive to make while low temperature heat is almost useless, we have plenty of that.