[grozmovoi]

"Ruskie" vs "Rosyjskie" is a difference between common speech and more proper grammar, but in regular usage of the language they both mean the adjective "Russian". I'm native.

[mikrl]

I assume the average person does not care about what Rus’ means versus Russian, Belarusian, and so on?

Is there a tendency to group them together? As Russians or as Rus’?

There is a lot of cultural context that Western Europeans (inc myself) are not aware of.