Original Sentence:
Mr HO will continue to be paid a salary by X Corp at the annual rate of $300,000 unless, before the end of the year, he finds employment elsewhere.

May I rewrite as follows with same meaning?
Unless Mr HO can find employment from elsewhere before the end of the year, otherwise, X Corp will continue to pay Mr HO a salary at the annual rate of $300,000

And Would you please advise when to use passive voice and when to use active voice?

Thanks.