For microtrust, I don't see any reliable way of knowing who ppl trust and who they don't. For instance, I don't trust my bank, but I use them because it is too difficult to transfer all my services to another bank. And, if I did, I know for a fact I would be faced with the same level of bad service I get now. I can think of some major merchants that I dislike, but I still patronize their businesses for the sake of convenience, or because they have what I need and nobody else does. My primary loyalty and trust is, however, price-based. I usually buy the least expensive goods I can find, of equivalent quality. And speaking of quality, raise your hand if you have been the victim of our disposable culture, where products you buy break within a week or two of normal use.
Technically, you may not 'trust' your bank, but as long as you let them handle at least small amounts of your money, even if just for the time it takes you to drive to an ATM and withdraw it, you're extending microtrust to them. Any service you purchase something from, or give them your credit card, you're extending microtrust to. You might only really 'trust' close friends and family members, but our societies commercial activity depends on microtrust already. Extending this to the crypto space will be a good thing, as in crypto the only person you really need to fully trust is yourself and the way you store your wallet. But sending a few dollars in crypto to a website so you can use their services can sense too. You only risk what you choose to transact.
Speaking of e-fiat, I noticed that Poloniex started trading in 'coinomat XUSD' which is interesting. Apparently you can redeem this XUSD to your visa or master card for real dollars. And I agree that all fiat will eventually only exist in electronic form. We're almost there already.