way2983

As others have pointed out, the difficulty adjusts both up and down depending on the total work being done by the network, so no death cycle is possible.

It's true that the difficulty adjusts both up and down, however it does so over 2016 block intervals. If a sufficiently fast and large drop in value/hashrate occurs, the chain could well 'death spiral'. The drop simply has to occur within the adjustment interval (2016 blocks- or 14 days).

That said, recovering from a death spiral is as simple as a new Bitcoin Core release that hard-forks the difficulty to a new, workable level, so the fatalistic view of death spirals is still wrong.

So, the selfish question then is: How do I protect myself from such unwarranted searches? Is there a way I can present my phone such that it drops into a mode that contains no data? Do I need to back my phone up before traveling, wipe it for the border crossing, and then restore once I feel safe?

Save your encrypted system configuration/data on a service. Leave all your devices behind. Buy new devices on the other side of the border, and restore from the encrypted backup. This is really the only way to completely sidestep the risk.

fuel adoption of crypto and speed up the demise of parasitic middlemen who take a cut off every transaction

Most business owners do not have the technical ability, interest, or logistical overhead to actually accept "crypto" (or cash) without "parasitic middlemen". This is why Coinbase, BitGo, et al. are very successful in this area, and account for virtually all cryptocurrency commerce. The function of Coinbase or BitGo is not parasitic; no business wants to cope with the arduous requirements to be able to accept and store cryptocurrencies.