Tsk, I'm worried about the Japanese r, too. But my issue isn't r being English but Spanish.
Here there is a tutorial for it if you hadn't checked it:http://overseasutau.forumotion.net/tutorial-and-resources-directory-f31/how-to-pronounce-the-japanese-r-dialect-comparisons-t1117.htm
Well, aside that r sound that pierces Japanese, heh, I still love Kurisu voice. He's very cool sounding, really.
When you end that r fix make him sing more! He's got only three covers in a month (well, it's probably not a bad number... I just think he could do something like hidalgo or pane dhiria, something with a more epic touch).
Now with Aster Selene's Essential UTAU Toolkit there is no reason of Japanese being in an ust and not being able to read it with English only computer:
I agree I don't see very nice to be too exclusive with the not overseas UTAU in the description. I would love to see more Japanese users around this forum (there were some, isn't it?).
All of the UTAUs are part of the same global world domination plan, anyway (j/k).