You are right. AFTER you have worked on your visa Working Holiday Visas without LMO (you do not need it on such visa and nobody will apply for LMO for you on such a visa and nobody issues it for you) ,you have to get a job with LMO to work another year and then apply for PR (PNP could be the shortest way because, usually you can apply as soon as you secure a job offer for permanent full time job with LMO and in some provinces from NOC 0-A-B, im some- they do not care about NOC)The visa entitles me to work for just one year, and in order to get PR status I should find a job that's "LMO-able" and after having worked at said job for 1 year I can apply for PR status. That's how I understood it, that's how one of my friends got his PR status.
I'm not sure the WH visa can be extended.