Headscratchers / StreetPass Mii Plaza

• Why do I keep seeing guests show up in my plaza who have never ever updated StreetPass Mii Plaza? I've been to events where I pass by people and see them playing the game, and while I'm delighted to sometimes see my Mii onscreen when I pass by, half the time they're not wearing a hat, even though I always have on a hat from outside of the first expansion. Doesn't the 3DS automatically update StreetPass Mii Plaza? Are they purposely turning down the update requests? Do they live in places where the 3DS can't connect easily so they're unaware of the updates? I noticed this tendency for people to never update the game was acknowledged in the Drinking Game here though.
  • Sometimes it asks the player directly, sometimes it just relegates it to the end-of-the-queue "Check for Updates" button and never notifies the player again until they check it. But never automatically.
• Also, the Miis whose last-played game is Health & Safety Information—what were they doing right before?
  • It's possible that they have been setting up their 3DS for homebrew hacking. One component to it is converting the Health & Safety app into a file installer for homebrew applications since it's a application that won't be missed even if something goes wrong. Though as of this writing, this method is relatively outdated since many people will simply revert their Health & Safety app back to normal after they're done installing a separate file installation app through it.
• So what exactly are green slimes in Find Mii to be so evasive? Even if you get a team of two light blue Miis to freeze them solid, attacks will still miss.
  • Maybe the slimes only have certain parts of their body that are tangible enough to take damage, and the "missed" attacks are just the Miis hitting a part of them that's too squishy to take damage?