Might contribute a few notes in replies to this tweet, which is clearly not going to be a happy Twitter experience but we work with the software we have...
The ticket system improves cleanliness in a wet, steamy environment. (More quietly: inventory control.)
Fun fact about vending machines: the engineers of them are Very Serious People. For example, substantially all Japanese drink vending machines can be circumvented to dispense free drinks, by design, for emergencies.
On that day, you don't want to have to guess, so you put elevations where everyone will check.
(Translator's note: The location you're being welcomed to is implicit in the language and heavily implied by ようこそ being the name of the international tourism program.)
(This sounds like an exaggeration. It is not.)
(You'll also see many more behaviorially disabled children in public than in the US. Deep topic.)
Because some bright individuals figured you can get on at Tokyo station, purchase an in-and-out ticket, travel across country, meet a confederate with 2 in-and-out tickets at station, and steal $200 in service.
The letter/number combo is folks for whom Meijijingumae might be hard.
"Why on earth would you do that?" Telegrams are the socially accepted way to deliver your regrets that you could not attend e.g. a wedding.
Costs $50~100 or so; ~$20 w/o doll IIRC.