Tipping etiquette is far from basic and almost downright intimidating. Even when I thought I had tipping at restaurants under control, I then lived in fear of embarrassing myself not tipping people in hotels and I'd stayed in a dozen hotels before I suspected that the maid cleaning the room expected a tip! Once got caught without change in a bathroom in a club in Hollywood and was so embarrassed that I handed over $10 foreign currency to a guy who handed me a towel - insane on every level.
Restaurant tipping in the US is fairly standard and shouldn't be too confusing or stressful. But I know exactly what you are talking about with other situations. For what it's worth, Americans are sometimes uncomfortable and don't know what the heck to do either! Hotels can be especially confusing.
Basically restaurants are the only place where tips are absolutely expected and you can make yourself look bad by not tipping. For anything else, if I'm not sure I usually just check a travel guide or go on forums and ask other people what they do.
I would do this if I travel to any country, just ask around at how you should behave if you want to fit in.
I've been to 30+ countries and the US is the only one where you'd need to research tipping beforehand. The notion that you'd need to hit up a forum to learn how to supplement certain wages in very specific situations in a hotel is pretty silly!
You even admit that locals barely know what's expected in some situations!
