You've got a good kit. But get yourself a tripod to get a steady panorama. Even an ultra wide angle lens could not give you 360 Degree view, so you need to stitch multiple photos so a tripod will allow you steady horizontal movement. With regard to your battery problem, A DSLR would last longer since you can use the viewfinder instead of live view..A battery grip would add extra durability..
But for now, you can get yourself an extra battery or two... Hope this helps...
btw, the info you've given was useful... learn somethin from it.... thank you.. :-)