i agree with your statements. it is far less combustible than roof shingles. under intense heat the tar melts but for the most part it is actually tough against fires. it was a forerunner to both vinyl and aluminum siding because this was available far before aluminum siding was. it is IMPOSSIBLE to repair if exposed to sun for a long time the material falls apart and looks like swiss cheese, the only way to "repair" it would be to cut the bad portion out and replace it, which would be difficult to do because A) its hard to find and B) the color wont match unless you find an abandoned house and rip it off of it. its advisable to cover it if it is in bad shape. adds an extra layer of insulation but this stuff degenerating can be an eyesore. insurance companies may recommend that you cover it up but unlike a damaged roof, they cannot deny you insurance.
