A course can be repeated once for "grade forgiveness."  Only the most recent attempt/grade will count towards the grade point average, but both attempts and both grades will appear on the official transcript. Retaking a course requires prior approval on the "GRADUATE COURSE RETAKE APPROVAL FORM​" available from the Graduate School website. Note only courses designated in the graduate bulletin as "not repeatable for credit" can be retaken this way. Grades for courses that are "repeatable for credit" cannot be forgiven this way. 

This is possible if your advisor agrees that the work you did for CSE599 would be equivalent to CSE523 (CSE523 and CSE524). If s/he does agree, discuss with the Graduate Director. If s/he does not agree, then you have to redo CSE523 and CSE524. Note also that such conversation, when approved, only means that one course is acceptable in lieu of another for the purpose of counting graduation credits. This will not change your official transcript.

This is possible if your advisor agrees with this. Discuss with the Graduate Director. It would be of your best interest to discuss such conversions sooner than later. Note that such conversation, when approved, only means that one course is acceptable in lieu of another for the purpose of counting MS graduation credits. This will not change your official transcript.

You can start working with a different professor if you wish. However, in that case you have to redo CSE 523 if you still want to do the Advanced Project Option. Generally speaking, you cannot do CSE 523 and CSE 524 with two different professors as they are meant to be on the same general two-semester long project. The other option is to drop down to the Basic Project Option and take a CSE 522. In either case, your CSE 523 with Professor X will not be counted as a part of the 31 credits required for graduation.

Some areas in computer science are more popular than others and professors in some areas could be busier than others. You can explore whether you can work in another area, or choose Basic Project Option for graduation.

Yes, so long as you do not have any visa-related restrictions. (For example, if you are on a student visa, you are expected to be full-time.) Also, note that most of our classes are offered during the day, and so if you hold another part-time job you may have to schedule your job-related work appropriately.

For international students, there are several restrictions. These restrictions are related to immigration rules and not due to academic requirements in the department. To understand things better refer to the CS department's Graduate Handbook and be conversant with the current Curricular Practical Training (CPT) policies of the Visa and Immigration Services (VIS) office. Generally speaking, an international student can go for internships in the summer as a part of their CPT only if certain reasonable conditions are satisfied (e.g., good academic standing, no incomplete courses, no outstanding proficiency courses requested at the admissions offer, at least two regular semesters in residence). Also, the CPT internships are meant to provide experience of industry practices in computing fields in a project of an appropriate scope (i.e., where a graduate education is needed). The student must concurrently register for the internship course (CS596).  Note that the CS department does not approve part-time or full-time CPT requests in Fall or Spring semesters. CPT requests will be considered for summer only. 

The internship is not a requirement. But the department and the university provide help to students interested in internships, including career center, job fairs, local advertisements over the graduate email list, contacts from the professors etc.