Can I get a schengen visa if my arrival and departure countries are different? Will my plane ticket be accepted in that scenario?
It's perfectly normal to stay in several Schengen countries and arrive/depart from different countries, the Schengen area has been created to make things like that easier. You don't need to worry about the plane tickets per se but you do need to present a coherent itinerary. Explain why you want to go to both countries, what you will do there (with evidence like invitation, bookings, etc. as applicable) and make sure to apply to the right country.
Yes. You file the planned itinerary with your visa application, and that itinerary has to make sense. It doesn't have to enter and leave through the same country.