Brother from Pakistan, I believe you are safe and carry on with your application as spouse accompanying.
1. You dont need to disclose any information as to why your spouse is non accompanying. The only requirements CIC has is Medical and Police clearance (PCC) even for those dependents who are non accompanying.
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=988&top=4
2. As soon as you receive your Permanent Resident (PR) card
3. Visitors visa is a lengthy process, you might be able to sponsor her earlier rather than getting a visitor visa
P.S. You should carry on with your Express Entry (EE) application as spouse accompanying. You have good Comprehensive Ranking Score (CRS)