As for the kanji, somewhere (here on WK?) I saw an explanation that went more or less along those lines (I’ve expanded on it a little).
Imagine that a $ sign expresses ideas related to money. When separated, $ is read “dollar”. But when part of a word, it can be read in different ways and it have different/specific meanings, for example:
- $inances (finances)
- $inancial (financial)
- $nomy (economy)
- $nomical (economical)
Similarly, © expresses ideas related to intellectual property. On its own it reads “copyright”, but when part of a word:
- ©tent (patent)
- ©cense (license)
- ©censing (licensing)
And, finally, we end up with:
- ©$ies (royalties)
It’s a simplification (doesn’t include jukugo words, rendaku, how kanji are built, radicals, sound marks etc.), but reflects how it all works well enough.