This is an ambitious itinerary but with it you will see a heck of a lot of the island. I suspect that was your goal. I don't want to tell you not to do this but I do have a couple of things that you should consider, since you asked.
1. If you have been to Isle Royale before and have hiked a number of these trails then ignore the following as you likely have a good idea of what you are getting into.
2. If you have never been to I.R. before but are a very experienced hiker (i.e. you have been on a number of backcountry trips that require this kind of mileage and/or you have learned to get by with a very lightweight pack on trips of this length/duration and/or you are such a physical specimen that pack weight and hiking distance don't matter [dubious]) then what you set forth to do is doable.
3. If you are inexperienced and/or prefer a lot of gear (weighty pack) on your outings and/or you body habitus is of the pork rind variety then I would advise some reconsideration on your part. Shorten overall distance and/or add more days to the trip so that you can break up some of the hikes you have planned into two days.
4. Consider your goals for the trip if you are looking to physically challenge yourself then you have outlined a great trip. The corollary of this is that you will have less time to explore and relax while you are in camp as some of your hikes will be very full days. None of your planned days would I consider "easy" days. Also you will not be able to sightsee as much along the way.
5. Never a bad idea to leave a day or so free in case of bad weather.
My take on your hikes is as follows.
Day 1 Arrive at *Rock Harbor* hike to *Moskey Basin
-Certainly a doable hike, I've done it. The Daisy to Moskey stretch will be the most difficult and the whole hike will take you some time, something you may want to consider depending on when you will arrive at Rock Harbor and won't be starting first thing in the morning... unless you take the plane.
Day 2 Leave *Moskey Basin* hike to *South Hatchet Lake*
-Again doable. One of the easier hikes you have planned. But again, not exactly easy, it just depends on your experience, pack weight, and conditioning.
Day 3 Leave *South Hatchet Lake* hike to *Island Mine
-Probably the lightest day you have planned.
Day 4 Leave *Island Mine* hike to *Feldtmann lake
-This is healthy stretch but can be done. Just consider that the most difficult, and probably the most scenic part of this hike will be the final third of it.
Day 5 Leave *Feldtmann Lake* hike to *Huginnin Cove*
-Should be a good day. Unfortunately I can say much about the last part of it as Hugginin and its associated trails are one of the few parts of the island I have yet to see. I hear it's nice though. Feldtmann to Wash. Creek will go quick.
Day 6 Leave *Hugginnin Cove* hike to *Little Todd Harbor*
-Unless I had something to prove to God and the rest of the world, or I was wanting to use this as a crosstraining workout en route to Ironman Hawaii, I would not do this. There is a stretch of trail that starts about 2mi west of the junction to N.Desor and continues all the way to the junction to L.Todd that is as difficult a stretch as any I have seen on the island. It's actually a very nice hike but it is physically demanding and your looking to do it at the end of a very long day. I should add that I did the stretch from N. Desor to L.Todd while it was wet and that compounds the difficulty substantially. This is your longest planned hike and over the most difficult terrain you'll see all week. Can it be done? I'm sure it can by some folks, but few would enjoy this day. I would break it up and stay at N. Desor for the night. Besides N. Desor is a nice place to stay and is always very quiet (a priority for me anyways).
Day 7 Leave *Little Todd Harbor* hike to *McCargoe Cove*
-A healthy hike of moderate difficulty, and a nice piece of the island. Enjoy.
Day 8 Leave *McCargoe Cove* hike to *Lane Cove
-An ambitious outing but doable. I've done it and at the end of a long trip like yours. The pack is lighter and your in the zone at this point which should help you to keep moving well. A long day though and make sure you include some time for the multiple overlooks along that stretch of Greenstone. Again the most difficult part of this trail is at the end of your day. It's even more difficult on the way out from Lane Cove. Lane is always nice though.
Day 9 Leave *Lane Cove* hike to *Rock Harbor*....leave island
-The homestretch and a great way to end the trip.
Hope this helps and have a nice time. Let us know how it goes.