Shouldn't a full time student receive a larger refund than a part time student? Testing by swapping blocks B and C in the T2202A shows that a part time gets more refund.

Full time students are generally not eligible for the Working Income Tax Benefit (WITB). The WITB is a refundable tax credit for people who work, but don’t make very much. Part time students are eligible for the WITB, which is why you see the larger refund when you say you are only part time.

Also, the tuition credit is a non-refundable credit. It can only be used to reduce taxes owing. If you have a refund, it will not add to the refund, instead the amounts will be carried forward to be used in a year when you do have taxes owing.