Answering your questions:
1. Activating our visa will give us 2 yrs of travel condition as per resident visa, is that a correct statement?
Yes this is correct.
So that we can enter NZ sometime later next year and look for jobs.
Yes this is correct.
2. My baby is due in March, how to get his/her visa done? as we already have our visa stamped and not currently in NZ.
Apply tourist visa for your child and travel to NZ and then apply dependent child visa. Lots of people go through the same situation and this would be straight forward.