A:AnswerYou can download apps on this TV. You can pair a Sony - DualShock 4 Wireless Controller for PlayStation 4 to play games. You can hook your laptop into one of the HDMI inputs on the TV.
A:AnswerYes, via download into the FireTv interface. They are not pre-installed, but it is very easy to do so. The primary APP is FireTV, then you install applications from there.
A:AnswerYES. Chromecast and FireStick would both work. There are multiple HDMI ports and even an USB port to power the Chromecast. But you really wouldn't need it with the WiFi capability, you can cast directly to the TV from your device.