Italy sings about a lot of italian things but if we're doing each different character then should we translate their version of the song? It wouldn't be fitting for a german to sing about how they love pasta XD Also if a couintry doesn't have a version, shoul the singer just make something up with thing fro mtheir cultures?
Also if someone is doing a european character then beware of pronounciations! Here's some I can think of off the top of my head:
ß = german character, pronounced 'ss'
Look up Palatal approximant! Some language pronounce 'J' as 'Y'! E.g, I have a lithuainian friend, his name is Jonas, it's pronounced Yhonas.
If you need any help pronouncing diacritical marked letter send me a pm =)