I was surprised by the weight, that is pretty low.
How long is this kit for? I am guessing an overnighter or weekend?
First, things I would add:
Soap - buy/find a tiny plastic bottle and get concentrated, biodegradable liquid soap, it does not weigh much at all. I think mine is like 25g (full of soap) and is an recycled hotel shampoo bottle.
Small towel/bandanna - good as pot holder too, also very light.
Lip balm/sunblock - kills two birds with one stone, mine weighs 12g
Whistle - just in case, mine is 10g
Paper/pen/duct tape - you can wrap a bit of duct tape around a free pen you get get from a bank or whatever, and a tiny memo book or just a few pieces of paper in a waterproof bag.
Ground cover - a plastic sheet or a space blanket is very cheap and only around 50-100g
Sleeping mat - I also sleep without a mat on occasion, but it has to be very warm, and I still use natural insulation. But most of the time a mat is a great thing to have, even if you are tough. Mats are a whole complicated choice and many people have several depending on the conditions or occasion. But your standard foam mat is cheap and you can trim it down to 3/4, 2/3, or torso only to save weight and bulk. I have one that I trimmed 2/3 and it is 350g with a strap to keep it rolled up.
Garbage bag - multi-use item (sit mat, water container, leg bivy, etc.) for only around 40-60g.
Compass - I only leave my compass at home when I am going to a place I know like the back of my hand, or if going with a group and someone else is bringing one.
Things I would switch:
Gsi SS cup for either a titanium or aluminum pot/mug. Not only will it be lighter, but you get more volume too, and because you don't list any water purification gear, I am assuming that you are boiling your water. It can be a pain to boil one mug at a time to fill your water bottles. My Ti pot is 700ml, and I usually boil half a liter at a time to re-fill my 1 liter platypus or whatever. Only takes me boiling two loads, and each load (using a good, hot campfire) only takes about 5 min. If money is an issue, get a big beer can, cut the top off, put a wire bail on it, and there you go.
Nalgene bottles for recycled plastic bottles. I have a 1.5 liter recycled ice tea bottle that is only around 65g, and it is the harder type plastic and has lasted me all summer and is still in perfect condition.
Extra boxers for extra socks. You use your feet more than your butt, so they tend to get sweatier. You can also go commando and wash off your boxers in a body of water, then tie em to your pack to dry as you walk.
Hope this helps. I, like you, am into bushcraft too as you know, so I dig what you are trying to do.