The case thing is an interesting point here. Essential themselves don't offer a case at present, and I can see how their accessory ideas would complicate that (different accessories would require different cut-outs to attach them - I'd guess the pins have quite a short travel). But there will be many people who care more about protection than about the accessories, so there certainly will be a market for cases. So as long as it attracts enough attention, cases will be available even if not from the manufacturer.
(Edit: a quick web search reveals a few screen protectors and a couple of cases already on offer).
I'd actually have reasonable confidence in the titanium protecting the device where it lands on that. It would be where it landed on the ceramic back, or the glass front, that I'd be more worried (the front, of course, being the same as any phone, and the back pretty similar to most flagships this year, since glass is in - perhaps a bit better because it's not curved, but there are different ceramics with different properties, so I don't have enough information to make a definite statement and hence am assuming it's similar to glass for the moment. This may be pessimistic but better that way).