Very interesting. If you can pull this off, it will be the absolute and final record of FS minimalism: the single brick font. For the sake of consistency I would use the solid circle for o. Don't bother to make lower case, nobody wants to use it to typeset the War and Peace. Instead, secure the best brick for each letter.
Very interesting concept!
I agree with Frodo about the O, but I think it´s cool that you used the LC to create UC alternates.
You might have to change the spacing on the I.








