First things first:
Don’t mean to sound rude, but I personally don’t think this is feasible for most people. If you think you can do it and find WaniKani too cumbersome, why don’t you try it out yourself with something like RTK and see how things go?
If you’re looking primarily to learn vocab, WaniKani is not the way to go about it (it is a kanji learning site first and foremost). There are a lot of other useful apps like Torii or Kitsun for learning core vocab.
Like Omun already mentioned, WaniKani uses these “radical” components to help form their own mnemonics. It’s true a lot of them are nonsense, but it is nonsense because that’s how the system intended to use them. Feel free to use your own (or official radical names and such) if you’d like in the notes and synonyms, as many of us do.
What you’re feeling is not uncommon for a lot of somewhat “experienced” new users (native Chinese speaker, already well into Japanese studies, etc) to WaniKani, and I feel obligated to point you to Naphthalene’s review of WaniKani as an advanced Japanese learner (completed WK after attaining JLPT N1…)