Those screenshots were from the Flaming Durtles (now Smouldering Durtles) Android app. Highly recommended if you do a lot of reviewing from an Android device.
You can also use https://www.wkstats.com/ to get more detailed stats from any web browser.
Don’t get hung up on the 15 lessons/day thing (it wasn’t even a thing back when I was doing my wanikani climb). It’s a decent default for newcommers but if you feel like you can do more, then just do more.
Correct.
Well, that’s one way to do it for sure, but keep in mind that many vocabulary entries are here to strengthen the kanji even if they’re not ultra-common words. I admit that I completely forgot what 私鉄 means but I could guess the reading at a glance, I think that’s the important part.
Personally I didn’t ignore the vocab, but I did make liberal use of “undo” (through scripts or Smouldering Durtles). I certainly wouldn’t care about forgetting the meaning of 私鉄, but you should be able to remember the reading and the meaning of the individual kanji. Of course it’s easier for me to make these calls now than back when I was on level 10…
Yeah unfortunately there’s no way around that if you want to go faster. I would recommend setting a short-term objective if you go down that route, like reaching level 30. I said I kept that pace to level 40 myself, but in hindsight it was probably a mistake, you really start hitting diminishing returns past level 30, you’re better off slowing down a bit on the kanji side and spend more time reading and studying grammar IMO.