Don't blame yourself. Sometimes even the best of us are not up for the challenge. Even though I can't live without my outdoor therapy I love my couch. :D
I have a nice opinion of this brand, especially about their batteries. In my experience they are even better than Duracell and Energizer. But I can't advise you about specific lamp models.
I've tried it a few times in the light snow and boy is it tiresome. If you're not in shape you won't enjoy it as much. :) But no one forbids you to try it.
I love to hike at night. First of all it lets me try all my flashlight and I'm a big fan of these. The only problem is that I have a hard time finding someone to go with me. :)
Is it possible to injure your shoulder by sleeping in an awkward position? I use my upper arm almost as a pillow and get incredible pain in my shoulder when I wake up. It gets worse as times goes by.
Do you know a web site where I can buy good quality affordable closed cell foam for my camping pads? I need bigger pieces out of which I can cut my own measures.
I think that one week would be pretty doable considering my experience. It would also depend on the environment. In some places it is almost impossible to find water.