"that" is wrong. "than" is correct. I guess this was a typo.
You can add "he does" but it's implied and unnecessary. There is no difference in the meaning if you add it or not.
As for "worked" or "was working", both are correct. "was working" gives the idea of his work as a continuous activity in the past, whereas "worked" gives the idea of a completed activity in the past. The meanings in this case are very similar and the tenses are interchangeable.