If you really want to shave ounces, post a complete list with weights. We can't really do much without 'em.

The Vario is a heavy filter. There are lighter ones that will be comparable in function.

Upgrade to an REI? You'll gain weight. To lose weight you'll be looking at Tarptents, Six Moon Designs, Zpack, and similar. There are 2 man tents that weigh less than the Spitfire, but you'll pay for 'em.

Make sure the BA pad is insulated if you want it to keep you warm. The Air Core is not. To go lighter you will be looking at the NeoAir as well.

I like headlamps - they work very well for all kinds of things. But if you have to have a lantern, the BD Orbit is pretty good in terms of lightweight light.

You can get lighter more compact bags, but you know that. If your destinations ever involve high elevation the liners won't work too well, but the bag will be overkill - people tend to have three season as well as winter bags for that reason, why sweat in a winter bag at 40 degrees? You might look at quilts for a lightweight three season option.
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