The application must include a letter from your employer indicating that they will support you and give you appropriate time off to take the various courses and work on your thesis. We reserve special MSc student status for those graduate students who are registered at another university elsewhere but are in Toronto for a short time and wish to take a course or two. I have been out of school for many years. We would strongly recommend that you take a few upper-level university CS courses before you apply. Only if you have specific research interests that match the interests of the faculty member and are applying for a PhD. It does not help to send a general application to individual faculty members.
Faculty members are very busy and most simply forward the e-mail to the grad office.
It doesn't help. This is especially true of people who send e-mail to lots of different faculty members. They are not looked upon favourably. We will forward it to Admissions unopened. We will not look at or evaluate such applications.