Voltage level of ADC: It depends on the device, anywhere between 3.0Vto 3.3V, sometimes 2.5V too. I advice you to review the datasheet of the part you are looking at.
The emulator helps you to debug the program from your development environment. You can either store data within the RAM and monitor offline or if you can send out data through SCI to a hyper terminal.
You can purchase an emulator separately. It is also available as part of the launch pad which costs lower. I recommend you to look at TI website for more details.
If your Matlab version is 2012 or later, it should be fine.