Most inspectors will want to do the "rough-in" inspection before you insulate or hang vapor barrier. That way they can see the framing, wiring, plumbing, etc.
Some inspectors do insulation inspections, some don't. Only your jurisdiction can tell you what they want for sure. Give them a call and ask. If I'm called to do a rough-in inspection and the house is insulated of a vapor barrier is up, it is coming down in most cases.
Clearance to can lights depends on the can light. If you're using type IC cans, they can touch the insulation. Most other can lights require some clearance to insulation and combusibles. The light's installation requirements are typically available online on the manufacturer's website.
No space is requried around switch and receptacle boxes. No insulation inside the box of course.