Disclaimer: Cryptocurrency is a great idea and i believe will be the eventual solution to corrupt central banks.
The biggest flaw with Bitcoin is going to arise from the very thing many people believe is its' greatest strength: the finite supply. The fixed total number of Bitcoins that will ever be created is not in itself the problem. The problem stems from the fact that bitcoins are perishable. Due to lost passwords, hardware error, etc. A small percentage of bitcoins are being permanently removed from the monetary base at a constant rate. This is fine in the short run as more bitcoins continue to be mined to replace the "lost" ones. However once all possible bitcoins have been added to the monetary base this gradual loss will continue. Extrapolating this phenomenon over the long term means a bitcoin monetary base will be constantly deflationary. This is great for savers in the short run but eventually the monetary base will reach such a low level that is will become prohibitive to easy economic exchange.
With the gold standard the monetary base was slowly expanding as new gold was mined and traded. Additionally, the rate of monetary destruction in the gold standard was never permanent like it is with Bitcoin, an individual could lose his sack of gold, but that gold never ceased to exist like a lost bitcoin does.
In order for cryptocurrency to work, i believe an analysis of this rate of bitcoin loss/destruction needs to be studied and a methodology to offest this monetary loss in order to maintain a constant monetary base must be established. otherwise you'll eventually run into a situation where the entire economy is being traded with the last remaining bitcoin in existence.
software guys...i'm looking at you to fix this!