As far as I know, the rejection rate is low as you already have the nomination certificate from the province (Alberta in your case) when you submit you PR application to CIC.
So I think you should feel confident enough to apply for PR application unless you have any serious crime records/security concerns/medical issues or problems of your job status (economic stability).
However, what matters is the processing time. Sometime they take really longer processing time than others if they think they have found more work to do on your application.
Nothing major to provide since CIC will let you know in advance if they need something (etc. extra documents/payments) but it's a waiting game that tests your patience.
and from current trend, it's getting slower. Hopefully the express entry will work better for future applicants.