Re: 3 question about bbPress
bbPress isn’t for someone who wants a program that can do everything including fixing your kitchen sink. It’s for people who want a slim, quick forum software that is highly customizable. You certainly have a good many plugins to choose from already, and the number is constantly getting bigger… for instance bbPress doesn’t come with stuff like private messaging, but you can easily install it using a plugin that some really smart guy created. But then if you feel that PMs aren’t needed in your forum, then you don’t have to install it and that choice causes your forum to stay trim instead of being bloated with features you don’t need.
However, if you feel you need everything packaged with phpBB, I think your choice is already made.
And to answer your questions:
1. I’m not sure, but I do know that a lot of different languages have been added to bbPress… you just have to install the correct files and I’m not exactly sure if there is a repository of them
3. The admin area is very slim with few options. Customization comes from theming and plugins. Plugins have the capability to add options to the admin pages (though none of mine do that yet… it’s on my docket)