A:AnswerAs far as I know, you have to use the monitor port, not the regular HDMI port to get the full function. Of course you still need something that will supply the screen with that much refresh speed.
A:AnswerYou can shut off the internet at any time and it works just fine. I don't know right out of the box though as I connected to wifi and got updates first, then disconnected it.
A:AnswerYes this monitor does have wifi capabilites, But i would not recommend using wifi with a high speed monitor such as this one. You should hard wire the monitor for best capabilities.
A:AnswerDoes your security camera system have an HDMI output? If yes, then this monitor will work. Will it be sufficient? That's not a question we can answer since you haven't given any details. What does that system recommend or require?