You have done a really good job. I have almost the exact same setup and it has lasted me for years. Worst case scenario you will learn that you don't like the small shelter and have to add a polycro side wall or something.
Don't waste your money since this is obviously your goal. It is a very well rounded setup you have dollar for dollar and I would just focus on purchasing one "upgrade" per trip from now on, in a way to strive for improvement.
What works for one person won't work for another for any number of reasons and I completely understand and respect your gear choices.
I started out with a gear list VERY similar to yours and have added a firebox nano, steripen freedom, my phone (invaluable tool), a SPOT GPS system, and a HH hammock/shelter (big investment think about your next shelter carefully). I've added/changed quite a few other things but I still carry my golite poncho.
On my next trip I will be carrying my vaporizer (i quit smoking) which is a 2600mah backup battery for my USB flashlight and USB water purifier, as well as my phone. It also means no more cigarettes yay! I also decided to go against my 1 item per trip rule this time and am adding a flamestower which can charge ALL the batteries I now carry in my devices over the fire for only 7 ounces (take the legs off and use sticks).
My setup is somewhere around 12lbs base weight or so now which as far as I can tell hasn't really gone up any since my original 8.5lbs or so I started with. However, I can stay out indefinitely now and not carry a single extra battery or fuel bottles etc. Every single thing I have that weighs heavy can fold flat against my back except my aluminum pot and I love the compactness of my gear. The weight difference is negligable when you reduce the bulk of it going from 8lbs to 12. Something else to consider.
My friend carries 60lbs of gear and is very out of shape. If you put your mind to it you can do anything so stick with what you have for now and strive for improvements based on YOUR experiences.
I learned a long time ago to take gear suggestions with a grain of salt around here. Most the guys that tell you what gear to buy are just justifying what they themselves purchased for way too much money to people like me and you. Time in the woods is what it is all about and your skill set is the most valuable tool you carry, not a $5000 backpack/gear setup.
I enjoy hiking with my friend because he enjoys time outdoors. I don't care what he carries or how he does it at a whopping 60lbs base weight. He enjoys himself and focuses on the outdoors more than 99% of people around here anyway. THAT is what I've learned from HEAVY packers, they are actually enjoying the experience in the woods more than the guy worried about his $1000 cuben gear.
I'll never forget when my buddy lit his pack on fire by accident one night with a little too much silly around the fire. Funny enough, he didn't even care because his gear is covered by redic manufacturer warranties and sure enough almost every item got replaced for free. That is when I realized my obsession was ruining my experience because had that happened to me I wouldn't have even been talking the rest of the trip, let alone shrug it off in a few minutes like he did.
Kind of ironic really as most people go lightweight to try and enjoy the outdoors more, not less, but then they get infested with gear bugs and obsessive.... need I go on lol.
I'm actually thinking about adding a frame pack to my arsenal too. Not a ultralight one either. The more I get into the woods the less I really want to deal with flimsy gear and soar shoulders or stuffing my pack JUST RIGHT like Goldi Locks. I've found through personal experience that my obsession over shaving a pound off my back in frame weight/comfort and durability is only detracting from my experience in the outdoors, not increasing it like most here are suggesting it does.
I've learned a lot from both heavy packers and light packers. I find myself as a middle ground kind of guy. I wish you luck in finding your balance too.