Quick clarification for Canadian PR

[ccl_00032]

Hi,
Just a beginner and want to clarify few things;

Is Canada allow Dual Nationalities
Time Required to Stay under PR before applying for Citizenship
Processing Time of PR
Can I sponsor my parents & siblings during PR status
Will I be eligible under Social Benefits or surviving benefits if i loose job or dont get it after three months or so (Worst Scenario-Hope it does not happen)?

Thanks