PLEASE SOME HELP

I have some questions about the Pnp Ontario for workers I really hope you can answer :
1) What happens if I get approuved in the Pnp and during the time I have a PR but I don't have yet a Canadian Citizenship I lose the job ?
2)Does the time I' m in Canada working on a work permit and waiting for CIC to approuve my permanent residence count toward the three years for the Canadian Citizenship ?
3)I have read that you need or 2 years of work experience OR an appropriate licence or registration in Ontario in a regulated profession to be eligible for Pnp Ontario, is it thrue that if I have the registration I don't need the 2 years of experience ? Is it long or difficult to gain this registrations ? How does it work ?
4)Is the timing ( 90 days for the approuval of the employer + 90 days for the approuval of my paccage + 1 year for the approuval of the PR ) right or does it take much longer ?
Sorry for all this questions , I really hope to be able to immigrate to Canada and so every information is very precious
for me , thanks in advance