I think you have to separate albino boxers and (simply) white boxers.
Albinism is known to generate several deficiencies in boxers, being blindness and deafness two of the major ones (but also kidney problems, if I remember it well).
"Whitness" is a different story. As long as the one of the parents has the recessive gene - even if they have no white at all - the puppies may be 1% to (close to) 100% white.
As Joanna mentioned, according to the breed standards, only up to 1/3 of the dog may be white. A few years ago there was a movement to change that - in the US or Canada, I believe - because when breeding the Canada champion to the All America champion, in 8 puppies...8 were more than 1/3 white. I donīt know, however, how things developed (apparently they didnīt)
Here in Europe, the breed standard remains the same: more than 1/3 white is not considered within the breed standards.
By the way.. I just love your puppy!
But Iīm partial... I just love white boxers

(Iīll post a picture of my 4 y.o. girl tomorrow)