In the West the predominant store-of-value right now is financial securities (stocks and bonds).

Mostly, yes. But gold still has a $7t market cap. But this does open up an interesting argument: that gold is on the whole dying as a store of value and it's being propped up almost entirely by tradition; in this case central bank gold holdings will probably decline 90%+ over the next century. In this scenario, BTC has no chance to replace gold because there's no new interest in gold anyway.

However, I would still argue that there is diversification value in BTC if it simultaneously manages to (i) have value increase proportionately to economic growth in the long term (that basically requires maintaining constant salience in a growing society), and (ii) be countercyclical to stocks; if that pattern repeats over two or three business cycles then I could see investment specialists advocating it in place of gold as part of an "all seasons" portfolio (essentially replacing gold here: http://mebfaber.com/2014/10/24/the-all-seasons-portfolio-aka-the-tony-robbins-portfolio/ ).

But I wonder why are you focusing solely on the store-of-value function, you don't think Bitcoin will be valuable as a medium of exchange?

A couple of reasons:

1. MoE usage brings much lower valuation prospects. You can see a currency getting to $10 billion simply from people trading it, but the serious $1t+ valuations come from people actually holding it in huge quantities. MV = PQ (where currency value is P^-1); M is constant, so the use cases that push P^-1 high are the ones where V is very low.
2. With MoE you can make a credible case that it will simply be continually replaced by superior technologies that improve on block time, scalability, anonymity, transaction cost, functionality, etc. Blockstream's sidechains project potentially allows protocol upgrades to come together with continued BTC use, but that itself is a bet. Also, for MoE people desire price stability much more, so my bets as far as cryptocurrency goes have been on stablecoins ( https://blog.ethereum.org/2014/11/11/search-stable-cryptocurrency/ ). So because of that last point particularly I would place MoE dominance probability at under 5%.

Depends on the resources brought against you, threat model still matters.

Agree. Anonymity depends pretty much completely on threat model in our high-info-inequality society.

Huh? I don't understand that. And, by the way, what is your point estimate? A mean? A median? Mode, maybe? :-)

$34000 is my "5% chance it will be above this" target (though my discussions here and in that debate have revised me a bit down to 2.5-4%). My mean is around $5000 I suppose, though I include only the 34000 * 0.05 rectangle in my final answer of $1700 as a sort of way of giving myself a safety margin. Median is under $200, mode is $0 :-)