Thank you for your concerns (and I'm not dismissing them!). I reread my OP and what you've written makes perfect sense. I wasn't completely clear on the details of the trip.
I'm not fortunate enough to have someone pick me up at the end of the trail. We have two cars, so we'll drop one at the finish and pile into the other to reach the start. It ends up being a lot of driving so it's easiest to sleep in the woods Friday night. Likewise, Saturday night will be spent sleeping in the woods as well. That explains the full sleeping/shelter thing. The trip isn't meant to be a 24 hour thing – the "challenge" of making the 45 miles merely has to be done in under 24 hours.
I don't have my scale with me currently and I high-ball estimations on weights when I have to make them. I don't think the base layer or the FA kit weigh as much as is written down (but I'm unsure). (As far as other weights go, those were verified with the scale I referred to.) I may end up leaving the base layer after all though.
Regarding the bag, I don't have anything lighter honestly. It says it's been modified; it compresses nicely into a much smaller size. It doesn't end up being cumbersome. Maybe that's hard to imagine though. This list isn't too far from my go-to kit for hiking trips (with the length of the trip dependent only upon how much food I bring.)
About the firesteel, good call. I've been needing to adjust that. While I can make fire without matches, I shouldn't force myself into that every time.
The lights: I didn't intend to carry a back up. I modified my typical hiking list into this one and forgot to take the smaller light off. You're right; it's unnecessary.
Ahhh, the boxers. For the past several years I've used new balance compression shorts which aren't as comfortable as they should be. I haven't taken the plunge on the Ex Officio ones yet; but the reason I've chosen them falls back on their reputation (which is startlingly superb). Taking them on a trip like this is risky – but I could always take them off. I've gone without undies on a hiking trip before and it didn't bother me (granted having them is a tad more comfortable).
I've saved the toothbrush/toothpaste for last. You're right I ought not bring them, maybe even if this were a list for a week long trip. I'll give the long answer at the bottom of the post.
Your comments are solid and much appreciated. I'm sorry I skimped on the itinerary – I ought to have been more clear.
Teeth stuff – I'm a junior at the US Naval Academy. I signed a contract to get braces (yes, technically a government contract). I get to keep them contingent upon superb oral hygiene; otherwise they take them off before the job is done and my pain will have been for nothing.