It is indeed hard to express bitcoins in that many decimal places, that's why we have mbtc and ubtc, just as we have micro, nano in real life to measure something on a small scale. I don't think that this will be a problem as the most conventional unit will be used throughout the time as bitcoin mature. Just take the cpu processor speed as an example, we refer to them as 1ghz, 2ghz etc instead of 1 000 000 000 hertz.

However, I do agree with you that the traditional bitcoin wallet takes a really long time for it to sync up. Fortunately, there are alternatives that let you sync with a network.