How can I program an SOC without a hardware kit?
They call it a system-on-chip, but you can also call it an ARM Cortex M0 microcontroller with Bluetooth and integrated DC-DC for a battery system with state of charge monitoring.

I suspect this chip can do what otherwise would have been done with 3 or 4 chips.


This chip might have tighter power requirement that your average Cortex M0 due to the wireless function. Including clock specifications.   
Yes. However this chip also features Encryption and Wireless which might require you to sign an additional NDA regarding patents and other politics.  
Well, you need to understand the datasheet and manuals to know how to spin a board with it. Then you must be able to write code for it. I suspect there will be some wireless code already available from the manufacturer.  


Maybe buy the dev kit first?