Well, it does mean that. Waifus aren’t exactly something they ruin their lives over (not counting the extreme cases). Sorry. I must not have done a good job explaining it. Urban Dictionary does a better job describing it than I do. You should check that out.
I’m autistic myself, so I kinda get what you mean. Not sure if Hank or Yukari have it, though, but I wouldn’t be surprised if they did.
Are you kidding? Hank’s just as quirky with either having undiagnosed ADHD or channeling dead crazy people. It’s like he’d be Yukari’s brother from another writer.
As for “waifu”, first, it’s how the English word “wife” would be pronounced in the Japanese language. It’s used by English speaking fans to refer to female characters they admire extensively to the point of wishing they were real so they could marry her/them.