Good starting point. I agree with waiting to change out your backpack last, after you've sorted out the rest of your gear. And plus, your pack weighs 34.87 ounces so even when you do switch it out for a light bag, it'll be a weight savings of 18-20 ounces or so, as apposed to multiple pounds for swapping your shelter and sleeping bag to lighter options.
Although your sleeping bag and shelter are heavy, the thing that stands out most to me is your 42.25 ounce sleeping pad. Pads that weigh ~18 ounces are considered "heavy". 42 ounces is the UL equivalent to carrying a king-sized bed! It seems to me that would be the first place to start, as it will be the least painful switch on the wallet. I currently use a Small Therm-a-Rest RidgeRest SOLite pad...Weighs 9 ounces and costs 20 bucks on Amazon. Plenty comfortable and decent warmth (R value = 2.8). I don't know your age or sleeping preferences, though...I'm 25 and could likely sleep on a bed of nails, so your mileage may vary. Even if that's the case, a great option for an inflatable is the Therm-a-Rest Prolite...Obviously more heavy, but perhaps more comfortable.
After that, I'd look to find a new shelter system. 84.50 ounces is a behemoth. Personally, I prefer a poncho tarp and bivy shelter system, although it did take some getting use to on my part and I understand that it's not for everyone. My Golite Poncho Tarp, bivy, ground cloth, and stakes weigh just under 18 ounces. I live in the U.S south-east and during the summer I just hammock camp, another relatively cheap and lightweight shelter system.
After that, I'd look to change out the 20 degree bag for a 20 degree quilt. In my opinion, quilts have made sleeping bags obsolete. Lighter weight and less volume for around the same price of a sleeping bag of equal temperature rating. Enlightened Equipment quilts are the standard for quality in the world of quilts, in my mind.