The core kata of Goju-ryu (which I practice) are based on lessons Kanryo Higashionna (Higaonna) learned in China over a period of about 5-10 years, depending on who tells the story. These are Sanchin, Sanseiru, Seisan, and Suparinpei. Higashionna himself called his art "chuan fa," or Chinese boxing.
Does that make it a Chinese art? Only if you think of Japanese as a Chinese language, because it uses Chinese characters.
I'd call it heavily influenced, but not Chinese.
What I'm curious about is where Saifa, Shisochin, Seiyunchin, Seipai, and Kururunfa came from. I know Miyagi made the Gekisai and Tensho, but no one seems to know where these other kata came from (lots of guesses and folklore, no verifiable facts). Perhaps Miyagi picked them up during his brief visits to China; perhaps other teachers added them. I can't find a straight answer, at least from a source I find credible. Just as an amateur opinion, Seiyunchin looks a lot like the Chinese internal style Xing-yi, to me.
As for Trias, I don't know what to think. I find all the grand titles he gave himself a bit silly, and inventing his own style a bit pompous. Sounds like he knew how to fight... whether or not he studied with a good teacher for very long, is uncertain. I guess ultimately we should judge a teacher by his or her students... and I have no idea how good a teacher his daughter is. She may be great. I haven't seen her teach.
