How can I support my WaniKani learning?

I can’t really help with item two as I’m still working on those readings myself, but this should help you with items three and four.

The Ultimate Additional Japanese Resources List!

As for item one, there’s a script you can find below that, once installed, will allow you to review what you’ve learned. I’ve noticed that there’s a difference of opinion on how helpful reviewing is to the SRS method of learning, but I’ve installed the script myself and have found it beneficial so far. Your mileage may vary.

[Userscript] Self-Study Quiz - #522 by rfindley

I’ll update this post if I find anything else that’s useful!