Speaking of mis-information...
Dept of Communications is the old name, before it became Industry Canada. Same mandate, different business cards. So if you hear somebody talking about DOC or Communications Canada, it's probably somebody who has been in the hobby or industry since before IC was IC.
A commercial radio is programmed to operate on specific frequencies. So you can't actually "attempt" to transmit on an amateur frequency if it doesn't already exist in the radio. Type-accepted commercial radios are not frequency-agile. Commercial radios modified to be programmed by the operator in the field are no longer type-accepted and cannot legally be used on commercial frequencies.
A commercial VHF radios' frequency range will typically cover all or a portion of the amateur VHF band. The amateur VHF band is 144-148 MHz; you will find commercial radios with ranges of 136-174 MHz or 146-174 MHz, or 136-152 MHz, or similar. So amateur frequencies CAN exist in a commercial radio, but they would have to be deliberately programmed that way.
Commercial radios may be used by amateur radio operators within the amateur bands. All of my VHF and UHF gear are commercial radios programmed with amateur frequencies, because they are better spec'd than amateur radios and have minimal controls for ease of use. This is perfectly legal; the commercial radios exceed the specs required by the amateur service.
If you are an amateur radio operator and have a license for your commercial radio, you can have your commercial frequencies and your amateur frequencies in the same commercial VHF radio.
However, amateur radios cannot be used to transmit on commercial frequencies, in part because they do not necessarily meet the specs required for use in the commercial radio service, and in part because IC does not want commercial users to be able to program frequencies on the fly, generally assuming that the commercial users are not radio hobbyists and therefore would not have the knowlege to correctly program a radio.
Funny thing, many hams like commercial gear, and many commercial users like ham gear.
It's not illegal to modify an amateur radio for operation outside of the amateur band, or posess such a radio, but it's illegal to use it to transmit outside of the amateur band (except in an emergency or during MARS/CAP activities). Some amateur radios such as the older Icoms came from the factory able to transmit outside of the amateur VHF band.
Licenses:
The Amateur Radio service requires the operator to hold an amateur radio operator's certificate. Each amateur radio station requires a license (callsign); this is different than your certificate. Your license covers all of your base, mobile, and portable radios at that location, and allows you to operate within any of the amateur bands (frequency ranges) for your license class. If you have a second base location, that location requires a separate license.
The Commercial Radio service requires the operator to hold a radio-telephone operator's restricted certificate. Each radio requires a separate license (callsign); this is different than your certificate. So if you own a mobile and a portable, you would require two licenses. You do not pay per frequency in the radio, but each frequency in the radio must be listed on that radio's license.
Greg