Of course they're being hoarded.
On the contrary, all the economic indicators point to the fact that, globally, Bitcoin spending is increasing: http://news.ycombinator.com/item?id=5296889 Perhaps people are uncertain about Bitcoin's future, or are plainly irrational, hence they still spend bitcoins despite knowing about deflation.
Multiple errors in your post.
The Bitcoin difficulty has never been bumped up by ASICs, because ASICs have not yet been released. They should come out in December/January.
Mining is still profitable today. I am still making money with GPUs (a little), and with FPGAs (a lot). Even after the halving due tomorrow, my GPUs will still make money. It is all about electrical costs. If you pay less than $0.20/kWh, a HD 7970 can still make money. Worldwide average is $0.10/kWh.
ASICs are not expensive at all. The most power efficient ASIC vendor, Butterfly Labs, have ASICs starting at $149: http://www.butterflylabs.com/products/
You are wrong. The "hoarding" argument has been beaten to death. Current evidence shows that people are NOT hoarding the coins: every day, 40 thousand coins change hands on the single largest exchange: http://bitcoincharts.com/markets/mtgoxUSD.html This is six times the number of coins created daily by the network (7 thousand).
In other words, people are not hoarding them, but are trading them very, very frequently.
And this is just measuring MtGox's volume. Other trades (merchant sales, other exchanges, etc) are likely doing even bigger volume...
Governments tend not to like their citizens taking part in transactions that don't have a paper trail.
You mean like... cash?
It's more than one engineer for god's sake... You too need to read the research papers!
We are just starting to be able to understand how to reliably reproduce it. See the table starting on page 16, more than a dozen groups have reproduced it: http://newenergytimes.com/v2/news/2012/2012Celani-WSEC.pdf
Real programs don't eat cache.