Hi
If you are already in Canada and have a work permit, why do you need your wife to sponsor you? I think she still could because a spouse does not have to show income to support but maybe you taking social assistance can affect it. Also, as the sponsor she is responsible for you so if you continue to take social assistance, she would have to pay it back.
Sure will, it will be obvious that the spouse is unable to support the OP, so the sponsorship would be most likely refused. Section 39 of the Immigration Act.
PMM