[How do department-allocated students are chosen at UCLA?]

According to their website, each department at UCLA has allocated housing places and offer them to their students. Do you know how the departments (especially ECE) choose those students?

[Class enrollment restrictions]

 

All American universities publish on their websites the minimum requirements of their master programs. However, I can't find information about class restrictions for most universities, notably UCLA.

Can a master student take more classes than the requirements of its program? Can students enroll in as many classes as they want?

Can a student enroll in classes that do not belong to their department? For instance, can a EE student enroll  in any CS classes?