You have a lot of warm clothes that could be lighter. First I will start with the Alpine Light Down Jacket; while this is a great down coat, it seems a bit overkill for the temps you mention. You could drop a quite a few ounces by going with a UL Down Inner or Ex Light.
I will also say that with a puffy insulating layer, you could go with something a lot lighter than Cap 3 for a “sleep” top. I use a Golite Silkweight L/S top that is 2.4oz. They don’t make them anymore, but I think the new Golite Wildwood Shirts are close. I don’t use it for warmth, just to have a clean dry top for camp and sleeping.
You could probably also cut some weight off your sleeping socks and bottoms as well. I use the same type socks I hike in (1.9oz Smartwool Adrenaline) and alternate every other day to keep (hopefully) a dry pair. You could also look into some lightweight bottoms like the 3.6oz BPL Merino bottoms.
The double rainbow is quite heavy for a solo shelter. If you don’t do much solo hiking I guess it works fine, but you could cut a pound off that shelter easily without giving up any real solo comforts.
I love window film as a groundsheet with a floorless shelter, but it is wasted weight on a shelter with a floor. I have a few sil floors that have 100+ nights of use in similar locations and they show no signs of damage without using a groundcloth.
I never have been a fan of BA IAC mats. While they were comfy and cheap, they were heavy and not very warm (defiantly not 15* warm!). If you can sleep on a CC Foam pad like a Ridgerest (~13oz) you can save weight, probably add warmth, get bulletproof reliability, and use it as a frame in a frameless pack. If you need the cushy pad, perhaps a Neo-Air or one of the new Pacific Outdoor pads would be a good fit.
I know a few hikers that absolutely love the Circuit, so I know it is a good pack, but it would be an option to go to a lighter framed pack (GG Mariposia Plus/ Gorilla or a SMD Swift ’11 with stay) or if you can sleep on a CC Foam pad, a lighter frameless pack, (SMD Swift minus stay, MLD Exudus, etc…)
It isn’t much, but you could change your toiletries bag out to a ziplock.
Cooking and Water:
I am not a bladder fan but they work for some people, and I imagine it works well with your gravity filter set up.
Your stove is light enough, but it might be inefficient with fuel if it takes 1oz per day in the summer (unless you drink lots of tea/coffee/etc.) Just something to think about.
The 0.9L Pot is a little big for most solo use unless you actually cook in it, in which case it is probably about right.
Some earlier suggestions would allow you to get rid of the sit pad.
Overall it is a nice list, some of my items are getting nit picky, but just food for thought.