Whether tap water is safe in the US depends a lot on where you are. In general, it’s safe to drink in that you won’t get any serious illnesses like you might somewhere else.
Nobody will ever say “make sure the cups are dry when they serve you” or “don’t drink the bottle if the cap is already off” (because it’s probably been reused). There a few exceptions where that isn’t true. You can search Flint, Michigan and what happened to the people’s water there.
The closer you are to major polluters from the oil and gas industry, the worse it can get. But even most rural towns have fine water from a single purification plant or a system of wells.
More likely what you’ll get is that the water can taste funny, because the level of minerals may be more or less than you’re used to. A lot of restaurants will serve you tap water and it isn’t a big deal, but you can tell by the taste.
At a minimum, most people I know use something like a Brita filter attached to their sink or as a separate water pitcher they refill. Maybe something built into their fridge, though that can be worse if they don’t clean it properly.
They sort of have. In that Utah is a Mormon state. It is controlled by the Mormon church. And I don’t mean in a “Jewish space laser” kind of way. I mean that Mormon settlers purposefully banded together in the area and Brigham Young’s entire deal was forming that Mormon state with the end goal of taking over the whole of the USA. Sometimes through force, sometimes through God willing it to them after the US eats itself from the inside out.
There were minor armed skirmishes between the government and state of Utah, nobody wanted to ratify Utah as a state for a long time because of the power it gave the Mormon church. There were several discussions about the possibility of going to war with Utah and whether that was preferable to letting the Mormons grow in power. The US army marched through Salt Lake City and they all fled the city or hid.
As others mentioned, there’s no realistic scenario in which Utah breaks away on its own. It would be immediately surrounded and cut off from resources. But in the case that the USA breaks apart entirely, they will try to claim their God given status as rulers of a new Mormon country.