First, you're mixing terms a bit and I wanted to set the record straight.
NTSC is a type of video formatting. The term you're looking for is NTFS. And yes, you should format all partitions as NTFS (unless you have a specific need for formatting as FAT32, but if that was the case, you would not be asking that question).
Regarding the extra devices, connect everything to the system before you install 7 so 7 has a chance to detect the device and get a driver installed right away if it has one.
16GB should be ok for the OS partition, but I'm not a firm believer in seperating the OS from the application installs. If something goes wrong with the OS Install, you're going to have to reinstall all of the applications anyway, therefore you might as well keep them all on the same partition.