A:AnswerThe K400 will not connect directly to your TV. It will connect to your PC that is connected to your TV. It will control anything being displayed from your PC to your TV.
A:AnswerIn the past, this would not work. In the present this does work. You just need the appropriate adapters. Wether that is lightning to usb OR usbc to usbA. see it in action below
https://youtu.be/ydcYF3-U0e4
Personally, i have tested my ipad mini (5th gen) with a k780 keyboard and an m720 mouse via one unifying receiver and that also worked flawlessly. Actually even better than it does over bluetooth. (Less lag)
A:AnswerNo, it's not Bluetooth. So you must use the included USB dongle or use the dongle that you may already have from another logitech product, like a mouse. I am doing that on my MacBook so that only one USB port is being taken up.
A:AnswerThis is a 2.4ghz wireless device not Bluetooth. If your android device supports OTG you can plug the receiver into your USB port and it works flawlessly but don't expect it to be connected without an adapter.
A:AnswerShouldn't be a problem, assuming you have an available standard USB 2.0 jack available on your laptop. The biggest issue you'll have then is the drop in functionality between your laptop keyboard and this product. I highly recommend finding a better quality keyboard, since it sounds as if you'll be getting heavy use out of it.