That's exactly what I'm using it for.
Yes, it's quite malleable.
Its intended use is for water supply lines for a refrigerator's icemaker so liquids that pass thru it are fine. Not sure how anything you might drink would come into contact with the exterior, though.
I think nearly pure copper.
I cut mine with a light saber. ;-)
I can't think of anything better to use!
YES, It is similar (but much smaller roll) to what I used to connect, & bury, exterior propane line - from tank to Iron piping in house . Interior of house - to gas log from Iron pipe - Aluminum tubing was used.
Or .03 each wall, 2 walls .06
Can't see why not, MUCH higher melt temperature