Hi there!
Here is my opinion about vocabulary. At your Wanikani level, you already know 86% of the JLPT N3 kanji, according to wkstats. Kanji is not vocabulary, but it’s close enough 
If you can get a few more levels before the exam, I am pretty sure it will be okay 
(you should be okay with you current level, though?)
To pass N3 this summer, I relied only on WK for vocab and almost aced the Language Knowledge section (vocabulary + grammar). Note that my WK level is closer to level 45 because I have transferred everything to Anki for convenience, but this doesn’t change the fact that WK was enough
I don’t have much advice regarding reading and listening, but I want to say how helpful jtest4you is. Of course, the more you read the news, watch anime and listen to podcasts, the better you will be. However, working through exercises that look like what you will face during the JLPT tests is precious.
(And I would like to add that the “reading” section is about finding the answer rapidly. See here about N2.)