No, it is not metal or plastic. The ends are painted black aluminum.
No, the hose does on leak at the fittings. I have it hooked to a hose reel and there may be a slight leak there because my compressor tank will go down over night if I don't shut it off at the compressor.
Hybrid/ Polymer - 'Stands up to outside weather to -40 below.
As much as any other hose. You would have to use a hose clamp just like you would with any other.
Yes you can put together as many hoses as you like, but that really depends on what it's going to be used for, because it's only 1/4" in diameter and productivity may drop from using extra long hose, also that would really depend on the tool's capacity
You will have to use different fittings that are available usually in the same section of the store. They do not come with the hose because there are different sizes and types of fittings
Yes, as long as it does not require over 300 psi.
No. Just threaded plastic ends like the picture. You will have to buy couplers.