Thanks for the number, do you have a link where you got it from? I suspected something like this might be the case, but I couldn’t find a source easily online.

By the time they’re going fast enough, they’re high enough they don’t have much air to worry about. (And they do have an angle over too, not just straight up)

Missiles do go more or less go straight though the atmosphere horizontally. Most are slower than what we’re taking about, but hypersonic missiles get close to rocket speeds. And they do need big heat shields to keep from melting immediately.