#1) Many more bitcoins will be in the hands of non-ASIC miners.
Completely irrelevant. The market price is what someone - anyone - sells at. We already know not all mined coins are being sold.
Your above statement proves lemonginger's point
#2) No other resources dynamically adjust their difficulty to a fixed rate. If you get a magic gold finding machine, the gold doesn't automatically become harder to find after you use it a few times.
The above is only relevant when everyone is using the same technology. This is the second time that won't hold true.
The system is technology agnostic...it doesn't care what is being used as long as about 6BTC per hour are being produced...this is where the difficulty comes in...