Your best bet for question number 1 is to email the uni they would be happy to answer that i am sure and yes you will easily get job essex also does criminology with a year abroad, usually in america which is what i have applied for, so its just how you apply the knowledge you learn, doesnt matter what part of the world you are in.
& also international entry requirements if you email them, they would be the best people
& Essex is actually one of the leading in the UK for research in social sciences so yeah a good school.