Add your own user synonyms if you want. WK can’t possibly cover every possible English translation that every resource out there covers by default.
There is functionally no difference between WK’s “to stop something” and “to make stop.” But you can phrase the same meaning a variety of ways in English, so that’s just something that you typically have to deal with with user synonyms.
As for the radical names, they are designed specifically for the mnemonics that WK makes, so of course they are sometimes unique to this site. Anyone not making the same mnemonics wouldn’t use them. The JLPT does not test radicals, so there really shouldn’t be any conflict with JLPT resources anyway. Someone studying for, say, the Kanji Kentei will need to know the Japanese radical names, but that’s beyond the scope of WK.