My nomination for #4 would be some sort of stove and fuel. Lots of choices, including some models that could run on automotive gasoline, I would consider an alcohol stove, something like the mini-trangia cookset, which costs all of $35, and is about the size of a typical canteen. Lots of options.

#5 should be some sort of tarp or shelter. Again, many options in different sizes, at different prices.