As it is capable of running a terminal emulator and SSH, as well as running on devices with a physical keyboard, Android is suitable for the OP's needs. Java doesn't really figure into this.

I believe this should answer your questions: http://www.ehow.com/list_6773348_braille-signage-requirements.html

That's an entirely realistic number when you consider the target audience for retail mainboards.

Well, hurry up then.