lol

Increase water intake? Yes. Most people who start keto lose a bunch of weight their first week, mostly water weight. For whatever reason, the keto diet seems to spark people to suddenly, intentionally pay attention to getting enough water.

Urine - it smells like ammonia when you first start :) After you become keto-adapted that goes away but it's pretty odd (and reassuring, to know you are successfully in ketosis) at first. I don't recall it changing in any other way, frequency or anything.

Stool changes - just about everyone who reports on it reports a change of some sort or another. I don't think it's entirely related to the diet though since it's not specific. It's more related to people diets changing and so their bowel movements change. Usually, though, the suggestion to newbies is to pay a lot of attention to getting enough fiber in whatever form. Veggies are best but fiber supplements are fine too (corresponds to getting more water).

Energy levels throughout the day - phenomenal! This is one of the most commented upon changes. With a lot of carbs in your diet, energy tends to fluctuate a lot. Energy from fat is longer-lasting or slower-burning or something, it's more even. The most common report from people is that they have energy all day now, when before they had to take naps or spikes and crashes. The second most common comment from people is that they have more energy.

Metabolism - normalizes, stabilizes. I don't know how much of this is due to keto specifically and how much is just due to the fact that most people are now tracking and regulating their intake. But yeah, whether you mean appetite or energy or whatever, it all gets easier.

I hit my target weight a long time ago and so I do allow myself some of the healthier carbs when they are presented to me (restaurant settings, eating at someone else's house, etc.) but for the most part I don't pick them for myself. I don't really buy any carbs when I'm grocery shopping. I just don't avoid them as much as I did when I was new on the diet. By healthier carbs I mean the gamut of veggies or whole grain breads. I still won't eat anything from cheap, white flour and I won't anything with pure sugar or HCFS in it.