Names in Japanese (in general, like first names, last names, places) are so difficult to know how to read, they often do not follow "normal" rules and can be quite creative (you could never guess some of those). Even though there are a lot of them that are quite obvious and common, sometimes you can really be surprised.
Typically, all paper work comes with two rows for names : one for your kanji name and one for the reading. And names of places (like in stations) are often written with furigana so you're sure how to read them.
I read on twitter that staff said there were around 6000 visitors from opening til the afternoon. The line went from the 8th floor to the 1st then again til the 6th floor... I felt 2-3h wasn't so long when you know the Japanese standards so I went to check on some blogs/tweets. Seems an average of 5h total to queue to get in + queue to go in the goods sales + queue for the cashier was quite a standard (add to that the time to queue for the exhibition, which seemed more feasible in the afternoon)