Yes, can come and do it at any JPN branches. Just bring along original birth cert of the baby/kid and you need to fill in a form for MyKid application.

If you want it fast, go to JPN HQ/State HQ or any distributed printing branches like at UTC (everywhere) and certain branches (I don't remember). You can get it within a day if there is no problem with the application.

Mind you all guys, MyKid is NOT compulsory to have. Birth Certificate is COMPULSORY.

Yes. You can just skip MyKid and do MyKad when your kid reach 12 years old. Birth Certificate should be good enough. But there are some sohai school/place deem the MyKid is compulsory and some customer come and complaint to JPN that why their kid doesn't have MyKid demanded by those places. JPN always will tell the customer that Birth Certificate is sufficed to do any registration because it is the valid documentation. MyKid is just a just a complimentary.