You'll see some beautiful country on your hike. Sucker River to Castle Danger is relatively level deep woods hiking (nothing spectacular there) but it really picks up once you reach the Gooseberry River.
Be aware of the current trail conditions shown at http://bit.ly/kgq7N9 ... in short it's been a very wet spring and that has continued into summer. Also there's a bridge out on Split Rock Creek (not River) ... fordable but be wary if it's been raining more.
About your gear list (many of these are "Your Mileage May Vary" things):
Sleep system ... I'd bring something less warm if that's available. Cold weather is not unheard of in July there's nothing like that in the current extended forecast (guess) ... lows no colder than 50 or high 40's
other clothing ... I'd drop the down inner
Given the wet conditions I'd bring an ounce or two of powdered laundry soap and a 2 gallon ziplock bag for laundering socks (and underwear while you are at it) ... also a couple ounces extra fuel to heat wash water.
Others may shoot me down on this but with the wet conditions I'd be packing something for camp shoes
I see no mention of maps. It's hard to get lost on this trail but it can be handy knowing distances to things. You can stop at the Trail Assn office in Two Harbors and pick up pocket maps for $0.50 each (free if you are a member). I think you'll need 4 different maps to cover your route.
BTW, 3 liters of water weighs approx 105 oz, not 35.2!