How do I finish Wanikani in 2 years or so?

If all you care about is the level, then as soon as you hit a new level you need to do all your lessons for your radicals then kanji.

Radicals open up for new kanji once they’re guru’d - therefore starting them asap make for getting the new kanji sooner

Then work on learning on the kanji and guruing them as they are what stop you from leveling up.

Then whatever vocabulary lessons you have, do ~ 10/day (or however many you want. They are the most useful for practical application)

This script allows you the filter your lessons to do them in whatever order.

What everyone else is saying is 100% true about studying and learning the language well, but this is just manipulating the order you study for the level up.