Generally, when describing a thing, the unit is written as singular. “15 minute delay”, “10 foot pole”, “5 gallon bucket”. When referring the unit itself though, it would be plural: “a delay of 15 minutes”, “the pole is 10 feet long”, “this bucket holds 5 gallons”. I’m sure there’s a more precise way to say this, but hopefully it helps.

Yep, you just have to set Keep as your default note service in the Google Assistant settings.

Shared notes in Keep sync very quickly in my experience as long as you have a reasonable internet connection.

There’s actually a tricky spot for folks who get certain social services which are tied to income. A small raise can bump you out of eligibility for things like medicaid and food stamps, and thus can in fact result in higher expenses, less money in your pocket, and a lower quality of life.