1) Why does it eat up so much CPU? It might as well be mining Bitcoin...
2) Why are the fiat values so high?
3) How do you take into account Bitcoins that are changing hands, i.e. I take $400 and buy a Bitcoin. Someone else then buys it off me for $410. $810 of fiat didn't 'leak'?
1) you are welcome to critique or modify the code as it is open source
2&3) each trade coming from an exchange gives an amount total of Bitcoins purchased, the currency that it was purchased in and the price that it cost in that currency. Fiatleak simply takes each trade and adds together the amount of Bitcoins purchased. As all trades are positive, this number increases...
As one form of exchange increases others decline, the answer to the question you are raising depends on where you draw the line of distinction between currencies of trade. I draw a strong line between fiat (those with banker chosen inflation) and bitcoin (mathematically enforced maximum resource limit) which is why the site presents the data in this way.
The fact of the matter is that all of Bitcoin's economic value at this point has been derived from a handful of engineers developing software and an even smaller number of engineers developing and selling hardware to a mining market that purchases a small bit of electricity. This goes to show that value is not a function anything other than acceptance, and it is why it is clear that the acceptance of a new currency like Bitcoin is actually taking away from our current system of fiat money.
If you want to argue more about it, let's do it on a hangout.