Kudos to you for trying it. You can't ask for more than that.
It's not single-click but for the amount of times you should actually be whitelisting sites (if that's the way you want to play, rather than just, say, having it switched on) it's not a hassle in the least.
Your Opera 10 problems are your own, besides the fact that we're on 11.51 now. On all the machines I've ever managed (that's how long I've been installing it as the default) the only problem I have is on a single server that has a known procedure_entry_point error because of a MCVCRT file compatibility problem. It still runs, it just pops up a dialog first. Hell, it even works from a single shared network folder for dozens of users simultaneously - and a lot neater than trying to bundle Firefox MSI's onto corporate machines (Ick!) has been in the past. Whether a clean install or an upgrade (like I say, my Opera profile is carried forward from some ridiculously old original profiles).
Now, the Japanese thing I'll have to concede - not because I know that Opera won't do it, but because I have never needed to install a non-western language into any installation, ever. But I'd be very surprised if there weren't half-a-dozen Opera "extensions" that did the same thing without executing native code, no need for the Netscape plugin API that's common to all the browsers, Opera included (how do you think we run the latest Flash, Java, VLC plugins, etc.?). (Opera Widgets are a security-sandbox for plugins that actually integrate into the browser much better - the equivalent of a Firefox extension rather than a plugin - and just as powerful).
Opera isn't "middle of the road". It's quite often "cutting edge" and other browsers play catch-up. That's kind of the point that most Opera users will make. You say "Oh, the NoScript plug-in adds that functionality" and we say "We've had that in the default build since before that plug-in even existed".
And that's BEFORE you even delve into a proper configuration dialog at opera:config (which does have EVERY option you can use, unlike Firefox which makes you plug some of the more obscure ones in yourself manually).
I don't require people to USE Opera, I just think they should actually seriously trial it. There may be use-cases where it doesn't fit, but it's the only browser I trust for every job from giving it to computer-newbies (it's pretty damn hard to break your computer by viewing sites in Opera, even if you try - years of experience has taught me that it's the only "safe" option that people really have a hard time trying to mess up) right up to installing it across hundreds of machines, kiosk-mode internet terminals (built-in kiosk modes, automated slideshows, and URL filtering to keep people on your intranet, for example), home use and serious IT Office use. And strangely, that's because it *doesn't* compromise - my home setup is much more complicated than anything I use in work, which is locked down immensely.