I did a trip in this area almost exactly a year ago. The bugs were fairly bad! You might want to wait till later in the summer, but might be okay with a bug net. The trip report is here:
https://www.myccr.com/phpbbforum/viewto ... 08&t=47488 (Although the photos aren't showing up today.)
In response to your questions:
"Nine Mile Lake" is actually about 8 km, so you should be able to paddle it in less than 2 hours even as a novice/int unless the wind is really bad.
Portage is easy to find. It's on a snowmobile trail. If you download the KMZ file in my trip report, you'll get exact co-ordinates, but there's really no need. Portage starts at the north end of the west bay at the top of the lake. I'm pretty sure there was a snowmobile trail sign at the start of the portage. Portage is pretty flat, with a couple areas that skirt the side of a marsh after you pass the hydro lines.
There are at least a couple campsites on a couple islands at the north end of Nine Mile Lake. I wouldn't necessarily count on them being open though. You might check the Ontario Crown Land Use Policy Atlas for the lake and see where you could camp (in a pinch) otherwise. It would probably be not too hard (but not too pleasant) to camp somewhere under the hydro lines along the east side of the lake if you needed to. Most of the cottages are at the south end of Nine Mile Lake.
There's definitely camping on Wolf Lake. There's at least one established site on one of the islands, and you could probably bush camp elsewhere there if necessary. You cannot camp legally on Fox Lake, Round Lake, or Burnt Lake due to the conservation area status.
My loop was up to Spectacle Lake, then eventually back down through Round Lake.
In the southern part of the area you'll likely see other people. It's a pretty well-populated area. I saw some kind of bear baiting going on on Wolf Lake, as well as a lot of activity (camp(s)) at the east end of Marsh Lake. Really, all the lakes had stuff going on (or had recently had stuff going on) when I went through. I didn't see any other actual canoe-trippers though and only saw people on Nine Mile Lake and Marsh Lake.
WaterHunter (a poster here) has a lot of knowledge about the area. If you're considering a longer trip through lakes in that area don't go without reading some of his threads/posts.