Thing one? This is the default setting in Finder Preferences:
That's right. Anything you leave in your Trash for more than thirty days will be deleted. By default. Good and responsible people always empty their trash on a regular basis, just as they brush their teeth after every meal and rotate their tires every ten thousand miles. Meanwhile, the rest of us chuck things out on a haphazard basis and then empty the thing out whenever guilt and self-loathing dictate we're supposed to. Most of the time that's just fine--after all, we pretty much all have massive internal storage with tons of space--so no harm, no foul. We don't, however, need our computers to do that kind of thing for us. If I had a nickel for ever document, screenshot, or .gif of a kitten having it's belly scratched that I'd thrown away and then decided I needed a couple of months later I'd have... okay, well, probably only about thirty-five cents. But you get my point. It's great to have options, but not to have them shoved down your throat by default.
Secondly, the Calendar.app in Sierra seems to be mysteriously unable to search anything back past October 2014. Either on Google Apps, Exchange, or CalDAV servers. It's not a spotlight issue, and it's not something that happens on El Capitan and back. Ostensibly there's a bug fix in the works, but until that makes a tangible appearance then you'll find me alternately glowering at my calendar or shaking my angry fists at a brooding and silent sky.