1. Mine and my spouse PCC for home country was issued on Feb 2016 and we have not visited home country since then, is my PCC valid for submission?
As long as it was issued after you last visited, it should be OK to submit. But it is possible that IRCC requests a new one for both of you, so if it takes a long time to get the PCCs, you might want to just apply for new ones anyway.
2. My spouse PCC has his old passport number on it, he has a new passport number now because his old one has expired. Is his PCC valid and can be used or I have to get it re-issued?
doesn't matter about the passport #
3. Under travel history for primary applicant, do I have to list my spouse travel history as well? Because there is a separate section for accompanying spouse with a travel history section for him.
You each need to complete a separate travel history.
4. Do I need to do a Canadian PCC and submit it along with my home country PCC? Because document list says PCC (multiple)
You do not need the Canadian PCC. It says "PCC (multiple)" because you have to submit PCCs for every country you have lived in (since the age of 18) for at least 6 months (excluding Canada). Many, if not most, have lived in more than one country. If you have only ever lived in your home country and Canada, then you only need one PCC.