I used to refer to them as American Embassies when traveling. If you're lost, tired, hot, thirsty, hungry, have to use the bathroom and don't have change for a public WC but you stumble on a McDonald's, they'll have all the amenities you mention and often a map of the surrounding area.
The (slightly more) premium version is Starbucks, which has all the above but is more likely to have a clean bathroom. Also more importantly, somehow Starbucks more reliably has WiFi you can connect to without having a working phone number to authenticate, which was a huge problem in Switzerland (I tried a McDonalds first, too, but needed a phone number).
All of the Starbucks I visited in Europe had locks on the bathrooms.
McDonald's in Patong, Thailand has no toilet (we went there last night). Not sure if lack of toilet is common here, but it wouldn't surprise me.
I once went to a McDonald's in Amsterdam. You had to pay to use the restroom and there was a person standing at the door who would hand you a 12 inch strip of toilet paper. God knows what you were supposed to do if you actually needed more. From my experience in dozens of other McDonald's restaurants, I was stunned to see this.
That sounds very strange; was it queens day or something else special?
Different countries and cities have different practices concerning what you get. Across the border in mainland China, the toilets will often be cordoned off for months at a time, and they skimp on providing decent air-con. In Tokyo, they throw everyone out from 2am to 5am for "cleaning".
I love this, definitely treated one of the McDonald'ses in downtown Stockholm exactly like this on a trip last week. All my meals were, like, $10+ there, but hey, it's Scandinavia, I'll take it. (The truffle onion burger and sweet potato fries were amazing btw.)