Mine was badly split at the snow line as I climbed out of it the second morning. I fixed it with tape and put it in my day pack, which is juxtaposed for emergencies. It can be reused, but will not stand up to everyday use.
It is a "tube tent" which has a small rope that you can tie between two trees or rocks or things and then then it holds up the top of the tube. Open on both ends. The small rope would work in an emergency and at least it provides a floor and a ceiling. It would be great in an emergency and that is all you have, but it is not a replacement for a reliable tent for regular use.
Its like a survival blanket that is connected on all sides (length wise) and open on the ends. It has a cotton rope (not high quality) for using as a ridge line. To see simular watch you tube video "http://youtu.be/UDNLip5IQJw"
I've actually used tube tents a number of times in a variety of weather conditions.
If you seal them, yes, you have a carbon monoxide trap. Fortunately, sealing a tube tent that tight (in the environment where they would be used) is extremely difficult.
"Wind proof" means that the material blocks wind without letting it through as some fabrics do. It does not mean that putting a tube tent up is going to be windproof from all angles.
As to making the tent comfortable, it's really not that difficult. On one end you make a brush (foliage, vegetation) "wall", fundamentally closing that end with plant material. This will help hold the (in theory) warm air in the tent, but will also breath at the same time.
The "open" end can be set up in a variety of ways. If you're in cold weather, you build your fire 10 ft or so from the "front door" of the tube tent. Build a rock reflector wall at the back of the fire to help radiate heat into the tent. The space blanket material will retain a good portion of the heat and make you nights much better.
Barring that, take your poncho, or your spare space blanket (carry 3 or 4 for the weight and cost) and tape, jam, wedge or "rock tie" it to the upper 2/3 to 3/4 of the tent opening. This allows a cross flow of air through the tent, once again, insuring against CO attacks.
They're not difficult, but they do take a little practice and a bit of anticipation of potential problems.