I would say, it is doable. I hope Berlin Brandeburg is running and the usual problems after an opening of an airport are solved at this time.

The only problem you might run into is, if you luggage does not make it in CDG to BER, as I doubt they will sent it to Croatia. As far as I know there is no interline agreement with DL / AF and Easy Jet, but maybe someone knows better, which would solve this problem.