Early adopters. Well, if Bitcoins were to replace all currencies worldwide, and only 21 million coins were ever produced, then Satoshi, with his supposed 1.5 million coins, would hold approximately 7% of the world's currency. And you don't see that as a problem? Even if we only consider US money supply, which is around $14T, he would be holding $1T. I know I am not the only person who has a problem with that, and I am sure enough people would have a problem with it to prevent mass adoption of Bitcoins. It's not that I would be upset that he had that much money, it's that I don't want to see anyone with that much power over the currency.
Just a couple of quick points on this: the daily Forex turnover is $4T, so $1T does not seem like such a big deal when viewed this way. Many markets have been much more cornered than this in the past, and every single fiat currency in existence now are good examples. Plus, unlike the central banks that control these, once Satoshi's money is spent, it's gone. No more can be conjured up. Plus, it's highly doubtful that all or most of it would be held on to during an extremely unlikely rise to $14T market cap, unless Satoshi has some serious Scrooge McDuck syndrome, or is dead.
Deflationary spiral was shown as a problem during the great depression, when the dollar was based on a gold standard. While it may not have been deflationary, it was certainly less inflationary than the currency we have today. The country entered into a depression, along with many other countries, and each country only recovered when it started printing more money. Also, as you have pointed out, raising capital for new innovations or companies will be extremely difficult while using a deflationary currency because the opportunity costs are so high.
While there was a correlation between deflation and depression during the great depression, based on the broader data this is not generally true:
http://www.google.ca/url?sa=t&source=web&cd=1&ved=0CBcQFjAA&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.147.6290%26rep%3Drep1%26type%3Dpdf&ei=9-lJTq_JH4HeiALqqMiTBw&usg=AFQjCNHyeqoF52JQhW83o9O-FDXdSQHJxAFurthermore, is it really clear that deflation was the cause, and not the result of the depression? It makes more sense to me that you need a wave of bankruptcies
first in order to destroy the debt based money in the fractional reserve system before you can get falling prices.
I'm no economist though, just pointing out what seems logical to me.