I did a similar trip a couple summers ago, early August. I had planned the same Day 2 as you but ended up stopping at High Dam. The Alders were a hassle and there was a couple coming the other way that gave up on them but I've seen worse. Probably could have made it to the next site but the 1st site at High Dam was a solid site. Being a bit behind on plan, I stopped at Graham's Dam instead of High Falls. From there I had planned on getting to Burntroot but between the heat and the continual uphill of the portage to Remona, I was pretty done by the time I got to Whiskey Jack. From there I did a fairly easy day to Shippagew (after I went up the Tim to Shah then Rosebary).
Big Trout to Misty should be no problem. I've gone down that stretch and didn't find there too much current. Haven't been to Iagoo but the trip from Misty to Mubwayaka won't give you much trouble.
If it were me, I'd add a rest day or split one of the days just in case.
(all assuming this isn't your 1st rodeo and have done similar distances before)