Answer: The canvas is 100% water proof, however due to all the components sewn into the swag there may be slight seepage until the canvas gets to its maximum shrinkage level. We recommenced some type of "Flyover" for protection from the elements in extreme weather. Read "Helpfull Hints" PDF.
Answer: Your body heat builds up inside the swag, you must leave open the rear flap (behind your head) to allow some heat to escape. Your sleeping bag should be appropriately rated for the cold.
Answer: Yes, Read "Helpfull Hints" PDF.
Answer: I would recommend a 2 person swag (Roy-l-Dual) as it not only gives extra room but allows for a partner .