Some of your points are valid, but I would not consider them criteria for a failure.
However, they do deserve comment.
Mutual mistrust between buyer and seller needs to be supported. This is the toughest problem. Right now, sending Bitcoins is not tied to receiving something in return, and is irrevocable.
So basically, you'd prefer if the functionality which is currently offered by third-party escrow services, would be built straight into the protocol -- in a manner that:
- a transfer occurs in two stages
- first the sender gives up their coins, but the receiver doesn't get them yet
- the receiver has certainty that the sender HAS given up their coins, and only they may receive them
- now if the receiver cheats, and doesn't send goods, the sender loses their coins, but the receiver doesn't gain
- whether anyone gains them (generator of the next n-th block, where n is sufficiently large to give a long waiting period?), or whether the coins are lost forever, is an interesting technicality
- if the receiver is honest, the second stage is entered -- and on final confirmation by the sender, the receiver gets their coins
I agree that this functionality on the protocol level would be neat. This transaction mode would have to be optional, though, or it might be incompatible with your second wish -- that is, faster transactions.
However, it would likewise be complex. Perhaps at some moment, a non-destructive way will be found to introduce this. I would not, however, hold my breath waiting. In this regard, Bitcoin is indeed less than perfect, and that's why we have escrow services.
The double-spending check system has to be as least as fast as normal credit card processing. Waiting minutes for the block chain to update is unacceptable.
That could generate a lot more network traffic, and I'm not sure how much leeway do developers have. It would be neat, though, for retail purposes.
Some price stability is needed. Value shouldn't change more than 1% per week, worst case. 1% per month would be better.
In wishing this, unfortunately I suspect you wish for flying ponies. Price stability can't be had at such an early stage of adoption. Consider the size of the world economy, and the Bitcoin economy, and the uncertainties in the future of the latter. No way could it be stable at this point. It is fit for use by those who can live with that.
A better way of launching the currency needs to be developed.
I wish there was one. I truly wish. But I haven't thought of one.