My recollection is that Zero sells heated grips as an accessory. But I have heated grips on both of my BMWs and I recommend heated gloves as being a better option. They keep your hands much warmer in very cold weather, don't require installation other than a 12V pigtail, can be used on any other motorcycle and cost less. Another option is to purchase some battery-powered heated gloves as are available from stores specializing in outdoor recreational supplies. Also, some motorcycle accessory catalog stores sell both rechargeable battery-powered as well as motorcycle 12V power system heated gloves.
I have yet to see a rear luggage rack for the 2012 Zero or a hard top box. But there are plenty of soft and semi-soft luggage options that will attach to the rear of the seat and over the rear of the fairing behind the seat, such as sold by RKA and many other brands. The same goes for soft and semi-hard saddlebags. There are lots of options, but some of the larger saddlebags are too big to fit the Zero's frame.
Attached is a photo of the 10-year old expandable RKA bag that I use every day to carry lots of stuff on my 2012 Zero S.