I took a look at the articles on conditional と、たら、なら, as well as some other articles and it looks like they really put a lot of research into them ! Excited to see where it is going.
Yes. I quickly checked, and 楽しみ is even listed in the article (it’s the second one that came to mind after 旨み, so not surprising :p)
I have no idea. I don’t even know how to look up the history of grammatical structures Carvs would know, I guess, but they haven’t been on the forum in a while…
悲しみ and 痛み are really common as well, which only further supports my question about them coming from the verb! Of course, it’s also possible that it went like
痛い --> 痛み (using general-purpose grammar) --> 痛む (because people do what they want in language), until 痛む was a generally accepted verb.
The fact that some of the most common ones have both 形容詞 and 動詞 versions is suspicious though…
And searching certain grammar points from Search Engine of our choice (Google, DuckDuckGo, etc) is considered not to be user friendly for the most user I think.