I think you are worrying way too much about animals. I have yet in three years of hammocking to be even approached by an animal while in a hammock - and I typically wake four or five times a night. Rarely such things happen, but it is very rare. Probably the biggest thing to worry would be porcupines taking your shoes during the night.
If you are relying on a hammock to preserve your life and comfort if you are stranded for a night in temperate weather, I think you are making a mistake. Without a tarp, without something to keep you warm, if the nighttime temp drops much below 70, you could end up being very cold and uncomfortable. Far better would be a poncho and poncho liner with 50ft of parachute cord. For less than two lbs you are in a much better situation to survive a range of changing conditions.
Would I take my full set-up on a day hike when I expected to return to base camp? Probably not, unless it was dead of winter at elevation, and I had doubts regarding my ability to keep to schedule. However, I would carry a poncho liner, nylon tarp, para cord, and my usual essentials...basically the same thing I have in my backpack when I go hunting.
In the end, I think hammocking is for comfort and somewhat increased flexibility. Certainly there are places you can hang where you can't tent but the reverse is most certainly true once you leave the woodlands. Staying warm is a real issue. I have worked on my setup to manage temps in the teens, but when it goes below that, I think real hard about my plans.
There is a rule of threes that some folks use for survival situations: You can go
- three hours without shelter
- three days without water
- three weeks without food.
Shelter means warmth and protection from the elements. If you want that from a hammock, you are talking about a self-contained product like the Hennessy. Minimum weight, without anything to keep you warm is going to be at least 18 oz, assuming the Adventure Racer meets your needs. From there the weights go up. Yes, you could perhaps just add a space blanket and be set. ..but for me, that means high summer only.
I do get concerned when people say they will only go out on "pleasant days." I have seen way too many (100+) some days who go hiking in national parks on pleasant days in jeans and cotton t-shirts with little else. Most of the time, they get away with it...however, just two weeks ago it took a number of people to get young man down from Old Rag in SNP with a broken collar-bone. If there had not been literally 200 or more people spread out on an 8 mile trail, it could have been worse.
Whatever setup you decide to use, test it! First in your backyard, then in the wild. You will need to know what the warmth limits are, and what you need to do to be comfortable. Hanging low and piling leaves or pine straw underneath will help. You may be just fine with the absolute minimum you are proposing, but I don't think I would be.
Ain't got no mo' mojo, but I got plenty o' banjo.