http://www.cic.gc.ca/english/index.html
have a read of this - you would presumably count as a skilled worker with the plumbing qualification. However you would need a police check to get into the country (police certificate) and i doubt whether they would be impressed with the criminal convictions and think this would seriously jepordise any attempt to gain residency there - crimes of violence and not just isolated incidents will probably be a bar to your entry
re driving - i have known people that are banned to drive in one country but able to drive in another, but don't know anything about canada's rules on this
good luck though