Ah that second rhythm is a little devil to get right but fun to play. I have never heard of the term ghost notes for drumming, thought its certainly a good way to describe them...maybe I just didn't have lessons for long enough to get to that point.

There's a thing on the piano where notes are referred to as 'ossia', which kind of means alternative version, though they aren't necessarily quieter or harder, just different notes written above on a tiny stave.