Hi,
The Sensinode Nanostack 2.0 LITE that is running on CC1180 is capable of handling about 20-30 nodes per gateway so it depends on how many gateways your are planning to use in your network. Your sensors would actually be connected to the host MCU, and RF data is sent over the CC1180. It is not possible to connect any sensors directly to CC1180, since it is a wireless network processor. All drivers and sensors are handled using your host MCU.
A wireless mesh network is formed autonomously with CC1180, using RPL routing protocol. All devices in the 6LoWPAN network can act as routers if they need to. ONly one gateway per 6LoWPAN network.
The license is included in the CC1180 chip price, so you do not pay anything directly to Sensinode.
You can create two/more network that are independent of each other using e.g. different frequencies.
-Jonas