Yes, you can develop any kind of applications.
If you are a myGaze customer, you can login to your myGaze Shop account (http://www.mygaze.com/shop) and obtain the myGaze SDK installer and manual. If you have further questions please contact our support team directly using our contact form (http://www.mygaze.com/support/contact/).
No, the functions are all the same. The only difference between the SDKs relates to the licensing model you want to use and the type of business you are.
You can obtain more information via www.mygaze.com/support/contact