You are right that if you were a student, your husband should be able to get an open work permit and kids will be able to join too.
I do not believe there is any requirement in CEC that your year of skilled work experience would have to be related to your studies. You should be able to get an open post-grad work permit after your studies.
Then again, if you were able to secure a skilled position now and a temporary work permit, your husband and kids could also follow and you could apply for PR after 2 years.
The link for gas fitter licensing in AB is here:
http://www.workdestinations.org/view_profile.jsp?occupationUserDatumId=20782&profileUserDatumId=20786&lang=en In some trades you don't need to do licensing, some you have to take an exam within 6 months of starting work. I have a hunch it might be easier for your husband to find a job and get a work permit as a gas fitter than for you to get a job as a secretary. Tradesppl are more in demand. If he gets a work permit as a gas fitter, he can apply for PNP as soon as his employer will sponsor him. Many employers will do it after 3 or 6 months so then you could have your PR going in a bit faster.
I am not sure how it works for somebody who is on an open spouse permit to get sponsored through PNP. You would have to ask the AINP, see
http://www.albertacanada.com/immigration/immigrate/ainpforms.html If he was a low skilled worker on a low skilled permit being sponsored through PNP, he would have to work 6 months before he could be sponsored.
Look for gas fitter jobs here:
http://www.jobbank.gc.ca/res_eng.aspx?ProvId=09&Keyword=gas+fitter&Student=No