Welcome and hello. I've heard good things about REI's 1/4 dome and the rest of that line. Why a footprint? Use a lite ground cloth if needed, I use polycryo from Gossamer Gear. An emergency bivy? If you have your tent, bag and raingear why a bivy? Sounds like you will not be going solo. If you are only using your summer sleeping bag, you only need one sleeping pad, assuming you are going where it will not get too cold (freezing) or snowy. A pillow, use a stuff sack and put clothes into it. Why a dry sack, use garbage bags or a garbage compactor bag for clothes or other gear you are wanting to keep dry in your pack. Nalgene bottles, those are un-needed, use bladders. If you need a stand up water container recycle a Gatorade bottle unless you think you need the Nalgene to use with the Steripen. You have a lot of small stuff that quickly adds up to a lot of extra weight. You could shave weight by getting lighter versions if you can afford it and if the additional gear is needed at all. My two cents.