You wanted to know what kind of weight improvements can be made off this, so here are my suggestions. They're what I'd do in your situation, not necessarily the best course of action for YOU. Most people on this site would say that this is light enough or even TOO light, but I wouldn't underestimate the power of cutting a few more pounds off.
In order of the easiest improvements:
1. Mail pieces of the guidebook to yourself or put the data you need on your phone. Save 100-150 g
2. Your hygiene/repair kit is massive in comparison to the rest of your gear. There's a lot of items in there, but you don't need it to weigh 242 grams. A good target would be saving 100g in total from that weight.
3. You've clearly made the decision to bring both the Neoair and the GG nightlight, but you don't need both. Have you tried a torso pad such as the nightlight on its own? Have you tried using your packpack as a pad for your legs? Losing the Neoair could save 209 g.
4. Do you have a 40 degree quilt to switch to during warm weather? In summer, you won't need the 20 degree unless you sleep very cold. Could save 150 g.
5. You said you're considering switching to a Poncho Tarp system. That's a rather big change, but one I'd recommend because it'll give major weight savings. A Golite Poncho-tarp would save 250+ g of raingear, even if its only used as a backup shelter. Using it as a primary shelter would save 370 g, although you might want to add in a 200 g bivy sack and ditch the 43g groundcloth, depending on your preferences.
So, that's about 1.3 kilograms of potential weight savings to choose from, if weight savings are what you want. Be wary though, because I am making these observations as somebody who doesn't know you at all and has no clue about your preferences or needs.
Note: I hate the American system, but I use it primarily. So I'm converting to metric for you, and my numbers might be off.