Road Movement and Hills

[Shad]

And are all the hill additions added on any hill hex or just when entering a hex with an elevation line?

I'm pretty confident the answer to this question is "only when crossing an elevation line" which is the same as entering for all practical purposes. However, that's nowhere in the rules. I suspect it is explained on the Terrain Effects Chart, which I haven't handy.

Sadly, I must leave the other questions to... others.