So to summarize your points, if Bitcoin, or what crypto-currency comes to dominate, becomes a serious global currency to rival that of the dollar, if it's horded and not used to transact or invest in the economy, which is a danger due to its deflationary nature, then that will have dire consequences. But so long as its used as a currency and not primarily as a value store, then it's not a problem. Which is concerning. What concerns me about bitcoin currently is that it's not used a currency, AFAICT most people use it as an investment vehicle. It is worth pointing out that not all crypto-currencies are deflationary. Ethereum for instance, has no limit on the number of tokens.