Easy Heat AHB-130 Cold Weather Valve and Pipe Heating Cable, 30-Feet

Can I apply pipe heat cable directly to pvc pipe?

Has anyone used this inside a gutter downspout to keep it from freezing solid?

So the description gives conflicting information. Is this tape good for 40F or -380? Which is it?

In using this heat cable to keep an RV hose from freezing, is it necessary to pre-wrap the hose with aluminum tape before the heat cable?