No, there is not a PC version of Snapseed.
Snapseed is specially designed for Android and iOS; You can also install Snapseed in Windows & Mac operating system with the help of the Android Emulator.
Android Emulator is free software that allows download & install Snapseed in Windows & Mac.
Yes, Snapseed is entirely free to use application.
Yes, you can edit RAW in Snapseed.
Snapseed is not officially available for PC, but you can Download & Install Snapseed In Windows & Mac operating system with the help of the Android Emulator.
No, Snapseed is a photo editor, you can not edit videos with Snapseed.
Snapseed & Lightroom both are best; you can create different effects from both applications, but Snapseed features very easy to use and simple interface. It will not be wrong if you say Snapseed is photoshop for Android.