Hi, and welcome aboard. I'm impressed when people just show up and post a gear list. I'm still working on lightweight too, it's very much a work in progress.

Just glanced at your profile - we hike the same mountains, cool.

My general comments, to start:

Choose between the steripen and the filter. If you are not going where viruses are a concern, which you aren't in the Sierras, either will work - though I have heard of steripen issues that would make me less likely to choose that, myself. Take Micropur tablets as a backup to whichever you choose, as filters clog and batteries fail. I've filtered from sources that looked dicey enough that I used both.

You can chop off some weight with a different tent - a Clip Flashlight would shave some off, a Tarptent would shave off more. Still more could be saved if you went with a tarp and groundcloth. Looks like you're interested in a Mid, those are good too - think I saw a used one for sale either here or at backpackinglight.com. I'm guessing you use the tarp for a kitchen shelter - you could pick up a poncho/shelter to swap for the rain jacket and have a dual use item for that purpose.

Three liters is a bit much for a day's hiking, unless you are going out in the desert. I usually find two is enough unless it is very hot. In the Sierras there's usually plenty of water to filter if you run out on the way.

What is in the first aid kit? I think mine, for hiking with a large group of casual hikers, weighs maybe 8 oz at the worst. And I pack everything including the tick puller.

I have a plastic trowel - I rarely take it anymore. A heel or a rock or a stick will work in most cases, but then, I'm not hiking around in hardpan. A tent stake (if you have a Y stake or something similar, needle stakes are less useful) will work too.

I know, the bag - but a high quality down bag will shave the weight in half and probably be warmer. It's a simple enough matter to keep a down bag dry in the mountains. I wonder if you are a cold sleeper, or if it's just the bag isn't accurately rated. I thought I was a cold sleeper until I got an accurately rated down quilt - it was absolutely spot on, rated 25F and I finally slept out with it in 25F weather - I was just warm enough to be comfortable but not toasty like usual. I had no idea the temp got so low until we got up and the digital thermometer stored the lowest night temp - plus the snow on the ground was a kick in the pants.

The other potential spot to shave ounces would be the bear can - the Bearikade would lighten you up some more, but at a hefty price.

The NeoAir was okay for me down to 25F, but colder and I would add a foam pad to it. FYI. Of course, you already have a foam pad...

The other thing - what are you taking for food? Dehydrate/rehydrate or fresh?