You don't need to unlock it to use it on Rogers. It's the same network.
You cannot use that phone with Telus and Bell, or anyone else in Canada because it's a GSM 2G phone. Nobody else in Canada has a 2G network. Bell only has 3G HSPA (not GSM) network so don't waste your money.
Yeah as far as I know, it will only work with Rogers, wireless companies owned by Rogers (Fido and Chatr) and mobile virtual network operators (MVNOs) operating on Rogers' network (7-11 Speakout Wireless, Petro-Canada Mobility, SearsConnect and Primus). Unless there is another GSM network in Canada at the regional level or something that I don't know about.