Is Belford University accredited? If I get an online diploma BA or higher, will it be accepted at other universities and employment agencies?

No-it is not!!
List of unaccredited institutions of higher learning - Wikipedia, the free encyclopedia
Office of Degree Authorization

No, if you want one, just print one on your computer and make up a college name,

To be accepted by another college in the US, it has to be accredited from a school that is reconised by the Dept of Education, or be a school that has an agreement with another college.

Please refer to THIS STICKY