Blake is meant to be Batman II
Not Robin. He just happens to have the name Robin, which I believe was Nolan's homage to the character. Personally I see more of Terry McGuiness in Blake than any Robin.
Agreed. That said I'm not really keen on seeing a John Blake as Batman film even though it probably could be made to work. For me Bruce Wayne is the Batman, period.
Now a proper Batman Beyond
film could be fun, but how many of the general audience beyond fans of the series would buy into this?