"Thank you, bye."
Yes. Cześć can also mean honour,glory,admiration i.e. Oddaję cześć Bogu.=I worship God (lit) I give glory to God.
That's why when you greet someone or say farewell using 'cześć' you say 'glory to you', but you don't even realize that. :) Of course cześć is 'hi' 'bye', the example above is a piece of trivia, explaining (possible) origin of the word.
cześć = honour, sława = glory.
So "Cześć!" could be understood as "I honour you!"
It's interchangeable, so yes. It's like saying "Aloha" in Hawaiian, something like that anyway.
It would have helped to mention that this can be used in both instances before going over the lesson.
Google translate says cześć means "hello." Thank you for the explanations.
It would work, it would just be even more informal (some could consider it even childish).