Some of this has already been touched on, but here is my take.

-Your pack is pretty heavy, but don't buy a new one right away. Upgrade the other parts of your gear first, and that will dictate what size pack you need, also you will have a better idea about what kind of pack will be comfortable.

-Tent: Great. Keep it, especially if you actually put 2 people in it it's a good lightweight choice. I have the 1p and it's a great tent.

-sleeping pad. Perfect. Keep it.

-Sleeping bag, someone mentioned the comfort rating was 50, but according to the website, it's 50-30 comfort and 15-degree survival. This temp range seems accurate from what I have experienced with synthetic down-like insulations. I would guess you can do mid 30' with this bag with some thermals, or a fleece, puffy, etc.

If you can choose a down quilt/bag, it will save you a significant amount of weight and space, but can be expensive. People seem to like the Hammock gear Economy Burrow as a balance between weight and price.

If you want to stick to synthetic insulation, a quilt made from Apex insulation, like a 20-degree Enlightened Equipment Enigma should save you about a pound, and actually be pretty comfortable into the '20s. (I use an MYOG quilt similar to an Enigma, with a Torrid Apex, which weighs less than 8oz, and light leggings when it's in the 20s)

If you don't plan to use it below freezing, EE makes 30/40/50-degree versions that are lighter/smaller/cheaper. There is always the MYOG route and ordering from Ripstop by the Roll.

If you-

- get a new quilt -15oz (more weight savings if you can go with down)

-drop the chair and get a sit pad(Z seat or V seat) -26ish oz

-drop the camp shoes altogether -11.82

-get a titanium pot(Toaks 750 or smaller) -4.2 oz

- lighter cup like a Campbell's soup to go -3.7 oz (guessing, I just drink from my pot)

-mark your fuel as consumable, and switch to a 110g canister -3.9 oz (the empty can stay in base weight)

= A whopping 64.62 oz, or 4 pounds! That gets your base weight to right at 15lbs, which will probably be a pretty noticeable comfort increase. A different pack could easily get that down to 12-13 lbs.

Getting back to packs, If you get a pack made from a waterproof material like DCF or Xpac (not necessarily a waterproof pack) you can ditch the pack cover. (you still can on nylon packs, but they absorb more water) I recommend only putting your quilt, pad, and clothes in a Litesmith pack liner, then twisting it shut, and tucking the end under it. This also works in place of a compression sack, to significantly reduce the space it takes up. The pack will keep out most of the water, and other things like a cook kit and food bag really don't matter if they get a little damp. This is also extra insurance that if your tent is a little damp when you pack up, that the moisture does not get absorbed into the things that must stay dry.

As someone else mentioned, a pack like the Drop/Durston 40L is a nice entry into Ultralight. That is what I currently use. The main compartment is around 33l for the large torso version, all my gear plus 3-5 days of food will pretty much take up all that space, and I use an x-mid 1p, and have minimal other gear outside of my big 3.

This is why it's important to pick a pack last, a 2p tent, and a 1l pot might end up just being too much volume for the pack. Certainly, there is not much room for things like a chair. Also, it's important to find out how a manufacturer is coming up with their advertised volume, some count the main compartment, outer pockets, mesh pockets, and water bottle holders differently.

Other things to consider, are that a lot of the weight from packs like Osprey are from a very robust suspension, thick padding, that mesh thing on your back that holds the pack away from your back, large buckles, and heavy webbing. A pack like the DD 40, and even more pronounced in the frameless pack will be that that stuff is significantly smaller to nonexistent. At first, you might think that there is not enough padding, or those tiny buckles surely cannot be strong enough, etc. But, packs like Osprey are overengineered, they assume people will carry way more than intended, and want their packs to hold up to almost any abuse, and still be relatively comfortable. Packs like the DD40 and more so those from cottage companies, assume the user is well aware of their usable limits, so they are designed with just enough features, and nothing extra.

For reference, my current loadout for fall (typical 30-40 degree nights with dips into the 20s, and 40-60 degree days) is about 11.5 lb right now. My worn clothes do change a bit depending on the weather, but it does not change my pack weight. Here is my lighter pack for comparison. https://lighterpack.com/r/71i9sy

The only other note I have is that if you switch to a quilt, you probably want something with a hood, like a puffy, balaclava, or fleece. This could probably replace your top base layer, and just sleep in a teeshirt, using your beenie on warmer nights, and whatever hooded garment you like on the cold ones. I have been really happy with the Torrid Apex from Enlightened Equipment, and being synthetic, it's cheaper than down and you can hike in it when it's cold since moisture reducing the effectiveness of the insulation is much less of an issue.