ARC Research positions and Peer Tutors at the Academic Success Centre are not a part of the GROW program. Hours worked would not count towards your 100-hour maximum.
Yes, as a student employee, your paycheck will include deductions for Employment Insurance (EI), the Canada Pension Plan (CPP), and CUPE union dues. Student Employees pay union dues and are subject to the CUPE collective agreement.
For general information about the program, visit the GROW Program page.