Ask away, even if I get bored (or, more likely, sleepy given the hour here) somebody else will reply.
WaniKani by default doesn’t let you “undo” a mistake, so if you make a typo or just make a mistake but you feel like you were close enough and it shouldn’t matter, you’re still screwed and the item will be demoted to a lower SRS tier and result in more reviews later.
You can modify this behavior with userscripts like Double-Check or third-party apps like Smouldering Durtles which let you literally “undo” your mistakes and try again. Helpful for dealing with typos and also for cheating on entries you don’t really care if you get wrong, like the meaning of 私鉄.
There are also scripts like Reorder Omega that let you automatically prioritize lessons and reviews that matter most for leveling up, saving you some manual picking.
Keep in mind that I haven’t been using any of these scripts for now well over a year (since I reached level 60) so I don’t know if they’re still the best in town.