Nozonde is closer to hope or expectation in English, hope but without necessarily any confidence or belief that something will actually turn out. Kare ra ga mada ikite iru to iu nozomi wa hotondo nai desu. There's little chance they are still alive.
So for a literal translation of the first one, I'd probably go with something like :
Nihonjin to hanasu tame ni, Nihonogo wo tsukaetai to omotte imasu.
Nihonjin to hanasu tame ni, Nihonogo ga tsukaeru you ni naritai to omotte imasu.